bluuebunny/crossref_metadata_2025 huggingface dataset:
Activity in the human amygdala corresponds to early, rather than late period autonomic responses to a signal for shock
Authors: Cheng Dominic T. , Richards Jennifer , Helmstetter Fred J.
Published: July 2007

Laboratory animal and human subject studies report that the amygdala is a critical brain structure that supports the acquisition and expression of conditional fear. Recent functional neuroimaging studies in humans have reported that activity in this region is closely related to the behavioral expression of conditional skin conductance responses (SCR). However, SCR waveforms following conditional stimulus (CS) presentation contain both early period and late period responses that may differ with respect to underlying central processes. It is not known whether amygdala activity corresponds to the expression of early conditonal responses (CRs) that occur shortly following CS onset or late CRs that closely precede UCS onset. The present study used event-related functional magnetic resonance imaging and concurrent skin conductance measurements to determine whether amygdala activity is more closely related to the expression of early or late period CRs. Increased amygdala activity was detected during the formation of early, but not late period CRs. Additionally, this pattern of amygdala activity did not dissipate, but persisted into late stages of the experiment. These findings are consistent with the idea that amygdala responding is critically involved in the generation of CRs formed shortly following CS onset.
A comparison of two techniques for inserting the Airtraq™ laryngoscope in morbidly obese patients
Authors: Dhonneur G. , Ndoko S. K. , Amathieu R. , Attias A. , Housseini L. E. L. , Polliand C. , Tual L.
Published: July 2007

We postulated that video‐controlled tracheal intubation with the Airtraq™ laryngoscope using the reverse manoeuvre instead of the standard technique of insertion could facilitate the airway management of morbidly obese patients. For the reverse manoeuvre the laryngoscope is inserted 180° opposite to that recommended, and once in place rotated into the conventional pharyngeal position. Eighty (40 lean and 40 morbidly obese) ASA I–III adult patients were randomly allocated to four equal groups to compare the standard technique to the reverse manoeuvre for inserting the Airtraq laryngoscope. Video‐controlled and clinical tracheal intubation characteristics were recorded. The reverse manoeuvre did not influence tracheal intubation characteristics in the group of lean patients. In the group of morbidly obese patients, the standard technique of insertion was not satisfactory in 20% of cases and the reverse manoeuvre facilitated, speeded and secured tracheal intubation.
An evaluation of cardiac output by five arterial pulse contour techniques during cardiac surgery
Authors: De Wilde R. B. P. , Schreuder J. J. , Van Den Berg P. C. M. , Jansen J. R. C.
Published: July 2007

The bias, precision and tracking ability of five different pulse contour methods were evaluated by simultaneous comparison of cardiac output values from the conventional thermodilution technique (COtd). The five different pulse contour methods included in this study were: Wesseling's method (cZ); the Modelflow method; the LiDCO system; the PiCCO system and a recently developed Hemac method. We studied 24 cardiac surgery patients undergoing uncomplicated coronary artery bypass grafting. In each patient, the first series of COtd was used to calibrate the five pulse contour methods. In all, 199 series of measurements were accepted by all methods and included in the study. COtd ranged from 2.14 to 7.55 l.min−1, with a mean of 4.81 l.min−1. Bland‐Altman analysis showed the following bias and limits of agreement: cZ, 0.23 and − 0.80 to 1.26 l.min−1; Modelflow, 0.00 and − 0.74 to 0.74 l.min−1; LiDCO, – 0.17 and − 1.55 to 1.20 l.min−1; PiCCO, 0.14 and − 1.60 to 1.89 l.min−1; and Hemac, 0.06 and − 0.81 to 0.93 l.min−1. Changes in cardiac output larger than 0.5 l.min−1 (10%) were correctly followed by the Modelflow and the Hemac method in 96% of cases. In this group of subjects, without congestive heart failure, with normal heart rhythm and reasonable peripheral circulation, the best results in absolute values as well as in tracking changes in cardiac output were measured using the Modelflow and Hemac pulse contour methods, based on non‐linear three‐element Windkessel models.
Optimal skin surface landmark for the SVC‐RA junction in cancer patients requiring the implantation of permanent central venous catheters
Authors: Hsu J. H. , Wang S. S. , Lu D. V. , Cheng K. I. , Wang C. K. , Wu J. R.
Published: July 2007

We compared four different skin surface landmarks, the lower margin of the right 2nd costo‐sternal junction (point A); the upper margin of the right 3rd costo‐sternal junction (point B); the lower margin of the right 3rd costo‐sternal junction (point C); and a point 5 cm below the manubrio‐sternal junction (point D), in 20 cancer patients undergoing insertion of permanent central venous catheters whose tips were placed near the superior vena cava – right atrium (SVC‐RA) junction under transoesophageal echocardiography guidance. The landmark was satisfactory if it was located within 1 cm of the SVC‐RA junction. Points C and D were closer to the SVC‐RA junction than points A and B (p < 0.0001). However, point C had the highest incidence (C: 70%, A: 0%, B: 20%, D: 30%, p < 0.0001) of being within 1 cm of the SVC‐RA junction.
Quantifying the impact of longline fisheries on adult survival in the black‐footed albatross
Authors: VÉRAN SOPHIE , GIMENEZ OLIVIER , FLINT ELIZABETH , KENDALL WILLIAM L , DOHERTY JR PAUL F. , LEBRETON JEAN‐DOMINIQUE
Published: July 2007

Industrial longline fishing has been suspected to impact upon black‐footed albatross populationsPhoebastria nigripesby increasing mortality, but no precise estimates of bycatch mortality are available to ascertain this statement. We present a general framework for quantifying the relationship between albatross population and longline fishing in absence of reliable estimates of bycatch rate.

We analysed capture–recapture data of a population of black‐footed albatross to obtain estimates of survival probability for this population using several alternative models to adequately take into account heterogeneity in the recapture process. Instead of trying to estimate the number of birds killed by using various extrapolations and unchecked assumptions, we investigate the potential relationship between annual adult survival and several measures of fishing effort. Although we considered a large number of covariates, we used principal component analysis to generate a few uncorrelated synthetic variables from the set and thus we maintained both power and robustness.

The average survival for 1997–2002 was 92%, a low value compared to estimates available for other albatross species. We found that one of the synthetic variables used to summarize industrial longline fishing significantly explained more than 40% of the variation in adult survival over 11 years, suggesting an impact by longline fishing on albatross’ survival.

Our analysis provides some evidence of non‐linear variation in survival with fishing effort. This could indicate that below a certain level of fishing effort, deaths due to incidental catch can be partially or totally compensated for by a decrease in natural mortality. Another possible explanation is the existence of a strong interspecific competition for accessing the baits, reducing the risk of being accidentally hooked.

Synthesis and applications.The suspicion of a significant impact of longline fishing on the black‐footed albatross population was supported by the combination of a low estimate of adult survival for the study period, and a significant relationship between adult survival and a synthetic measure of fishing effort. This study highlights the sensitivity of the black‐footed albatross to commercial longline fishing, and should exhort fishery management authorities to find adequate seabirds avoidance methods and to encourage their employment.
Aboriginal fire regimes in Queensland, Australia: analysis of the explorers' record
Authors: Fensham R. J.
Published: July 2007

ABSTRACT. The record of eighteenth and nineteenth century explorers' references to Aboriginal fire in Queensland was stratified according to fourteen vegetation typcs and season of fire. It was demonstrated that references to ‘current’ fire (i.e. flames or smoke) may not represent traditional Aboriginal activity and that many fires were lit to frighten or harm, to protect themselves from, or to signal to kinfolk the presence of the European intruders. Because of this interpretational difficulty the records to ‘current’ fire were treated separately from ‘past’ fire (i.e. burnt ground). The data were analysed as the number of observations per 100 km spent in each vegetation type for any one season to compensate for bias created by differing amounts of travel. The record suggests highest frequency of burning in grassland around the Gulf of Carpentaria, relatively high fire frequency of most coastal and subcoastal vegetation types and relatively infrequent burning of inland Queensland. The analysis indicates a propensity for winter and autumn fue relative to spring and summer fire in all vegetation types combined and in most individual vegetation types.
Climatic influences on fire regimes along a rain forest‐to‐xeric woodland gradient in northern Patagonia, Argentina
Authors: Kitzberger Thomas , Veblen Thomas T. , Villalba Ricardo
Published: July 2007

ABSTRACT. Influences of annual climatic variation on fire occurrence were examined along a rainfall gradient from temperate rainforest to xeric woodlands in northern Patagonia, Argentina. Fire chronologies were derived from fire scars on trees and related to tree‐ring proxy records of climate over the period 1820–1974. Similarly, fire records of four Patagonian national parks for the period 1940–1988 were compared to instrumental weather data. Finally, the influences of broad‐scale synoptic weather patterns on fire occurrence in northern Patagonia were explored.

Fire in Nothofagus rainforests is highly dependent on drought during the spring and summer of the same year in which fires occur and is less strongly favoured by drought during the spring of the previous year. The occurrence of fire in dry vegetation types near the steppe ecotone is less dependent on drought because even during years of normal weather fuels are thoroughly desiccated during the dry summer. In xeric Austrocedrus woodlands, fire occurrence and spread are promoted by droughts during the fire season and also appear to be favoured by above‐average moisture conditions during the preceding 1 to 2 growing seasons which enhances fuel production. Thus, in the xeric woodlands fire is not simply dependent on drought but is favoured by greater climatic variability over time scales of several years.

Fire activity in northern Patagonia is greatly influenced by the intensity and latitudinal position of the subtropical high pressure cell of the southeast Pacific. Greater fire activity is associated with a more intense and more southerly located high pressure cell which blocks the influx of Pacific moisture into the continent. Although long‐term changes in fire occurrence along the rainforest‐to‐xeric woodland gradient have been greatly influenced by human activities, annual variation in fire frequency and extent is also strongly influenced by annual climatic variation.
Ecological and biogeographical effects of forest disturbance on tropical butterflies of Sumba, Indonesia
Authors: Hamer K. C. , Hill J. K. , Lace L. A. , Langan A. M.
Published: July 2007

ABSTRACT. Butterfly assemblages within lowland monsoon forest were compared at four sites on Sumba, Indonesia that differed in terms of protection and exhibited associated differences in levels of human disturbance. A numerical method employing principal components analysis was devised for describing forest structure at each site. The first principal component (PRIN1) grouped attributes tending towards dense forest with closely‐spaced trees, a closed canopy and a poorly developed field layer, with trees that tended to be large with the point of inversion in the upper half of the trunk. The highest values for PRIN1 were recorded within protected forest, and PRIN1 values were considered to be a useful index of forest disturbance at each site. Species diversity of butterflies was highest in unprotected secondary forest, but was not affected by lower levels of disturbance. Those species occurring at highest density in secondary forest generally had wide geographical distributions, whereas those species occurring at highest density in undisturbed primary forest had restricted ranges of distribution, in most cases with a separate subspecies on Sumba. Overall, an index of biogeographical distinctiveness decreased with increasing disturbance, and this supports the hypothesis that the most characteristic species of undisturbed climax forest have the smallest geographical ranges of distribution. Species abundance data for butterflies fitted a log‐normal distribution at all but the most disturbed site. These results indicate that the pattern of proportional abundance of tropical butterfly species may be used as an ‘instantaneous’ indicator of forest disturbance, and that changes in the structure of tropical forests in S.E. Asia resulting from human disturbance, even within partially‐protected forest, may result in the presence of butterfly assemblages of higher species diversity but of lower biogeographical distinctiveness, and therefore of lower value in terms of the conservation of global biodiversity.
The physiological basis of seed dormancy in Avena fatua. VIII. Action of malonic acid
Authors: Adkins S. W. , Symons S. J. , Simpson G. M.
Published: July 2007

Adkins, S. W., Symons, S. J. and Simpson, G. M. 1988. The physiological basis of seed dormancy in Avena fatua. VIII. Action of malonic acid ‐ Physiol. Plant, 72: 477–482.

A low concentration of malonic acid (50 mM) induced germination in four genetically pure dormant lines of Avena fatua L. Sensitivity to this treatment was poor immediately after harvest but increased markedly during after‐ripening, indicating that the mode of action of malonic acid (50 mM) was similar to that of another organic acid, citric acid. Over the concentration range (10–50 mM) where malonic acid promoted germination, oxygen uptake was also stimulated, and this was before the first visible signs of germination. At higher concentrations (100–300 mM) where there was no promotion of germination, malonic acid strongly inhibited oxygen uptake. These results show that malonic acid has a dual effect on oxygen uptake and subsequent germination. Low concentrations (10–50 mM) act by stimulating the Krebs cycle and germination through an acidification reaction like citric acid, and high concentrations (100–300 mM) act by inhibiting germination through enzymatic restraint of the Krebs cycle.

The stimulation of both oxygen uptake and germination by three established germination promoters (sodium nitrate, citric acid and ethanol) was inhibited by a high concentration of malonic acid (200 mM) but unaffected by a low concentration (50 mM). These results show that oxygen uptake, and hence the activity of the Krebs cycle, are important processes involved in the dormancy breaking mechanism of these three promotors.
Correction of chlorophyll‐defective male‐sterile winter oilseed rape (Brassica napus) through organelle exchange: Characterization of the chlorophyll deficiency
Authors: Jarl Carin I. , Ljungberg Ulla K. , Bornman Chris H.
Published: July 2007

Jarl, C. I., Ljungberg, U. K. and Bornman, C. H. 1988. Correction of chlorophyll‐defective male‐sterile winter oilseed rape (Brassica napus) through organelle exchange: Characterization of the chlorophyll deficiency. ‐ Physiol. Plant. 72: 505–510.

As is known, the introduction of male‐sterile Raphanus sativus L. cytoplasm into Brassica napus L. results in male‐sterile oilseed rape plants, which display a temperature‐related chlorophyll defect. The influences of temperature and irradiance on this defect were investigated. Compared to a line of normal (green phenotype) male‐fertile oilseed rape, the male‐sterile line had reduced chlorophyll content, fewer chloroplasts per cell, an altered ultrastructure of the chloroplasts and reduced activities of both photosystems, although the relative amounts of the photosystems and the chlorophyll a/b ratio were similar. The lower activity of the photosystems is explained by a decreased functional antennae size and a reduced efficiency in the interactions between the nuclear‐encoded light‐harvesting proteins and the reaction centres coded for by the plastome. Some thylakoid polypeptides differed in proportion between the male‐fertile line with green phenotype and the male‐sterile line with chlorotic phenotype. Characters, in which the two lines exhibited differences, are ascribed to difficulties in molecular communication between the oilseed rape nucleus and the radish cytoplasm, which are combined in the deficient male‐sterile line.
Regulation by CO2 of 1‐aminocyclopropane‐1‐carboxylic acid conversion to ethylene in climacteric fruits
Authors: Cheverry J. L. , Sy M. O. , Pouliqueen J. , Marcellin P.
Published: July 2007

Cheverry, J. L., Sy, M. O., Pouliquen, J. and Marcellin, P. 1988. Regulation by CO2 of 1‐aminocyclopropane‐1‐carboxylic acid conversion to ethylene in climateric fruits. ‐ Physiol. Plant. 72: 535–540.

A high CO2 concentration (20%) at 20°C rapidly and strongly inhibited the development of the climacteric ethylene burst in apple (Malus domestica Borkh. cv. Granny Smith) and avocado (Persea americana Mill. cv. Fuerte) fruits and did not change 1‐aminocyclopropane‐l‐carboxylic acid (ACC) content. Treatment with 20% CO2 markedly decreased ACC‐dependent ethylene biosynthesis at 20°C in climacteric pericarp tissues. It is suggested, therefore, that high CO2 levels inhibit conversion of ACC to ethylene.

Synthesis of the ethylene forming enzyme (EFE) was enhanced when intact preclimacteric apples or early climacteric avocados were pretreated for 40 h with 10 μ11‐1 ethylene. When CO2 (20%) and ethylene were both applied, a reduced stimulatory effect of ethylene on EFE synthesis was observed. A high CO2 concentration enhanced EFE acivity in excised tissues of apples and avocados incubated with ACC (2 mM) and cycloheximide (1 mM) or 2–5‐norbornadiene (5 ml 1‐1). In the autocatalytic process, 20% CO2 antagonized the stimulation of EFE synthesis by ethylene, but promoted EFE activity.
The stimulating effect of a cold, dark pretreatment on the etioplast/chloroplast transformation of angiosperms. I. The stimulating effect of cold predarkening on different stages of greening under white light
Authors: Schönbohm Ekkehard , Stute Ulrich , Thienhaus Peter , Werner Ulrike
Published: July 2007

Schönbohm, E., Stute, U., Thienhaus, P. and Werner, U. 1988. The stimulating effect of a cold, dark pretreatment on the etioplast/chloroplast transformation of angiosperms I. The stimulating effect of cold predarkening on different stages of greening under white light. ‐ Physiol. Plant. 72: 541–546.

The etioplast/chloroplast transformation in angiosperms is controlled by light; most of the processes are mediated by phytochrome. We have shown that in the primary leaves of etiolated seedlings of wheat (Triticum aestivum L. cv. Kolibri), fire‐bean (Phaseolus multiflorus L. cv. Preisgewinner) and in the cotyledons of etiolated sun flower seedlings (Helianthus annuus L. cv. macrocarpa) the chlorophyll accumulation in the phase after the end of the lag phase can be greatly stimulated by a cold predarkening period. This effect is not necessarily coupled with a red preirradiation. Furthermore the lag phase can be dramatically shortened by the cold, dark pretreatment, whereas the amount of photoconvertible protochlorophyll(ide) in the darkness remains unaffected by the cold, dark pretreatment. The stimulating effect of a cold, predarkening period on greening is fully reversible by a warm, dark phase that is placed between the cold period and the onset of the continuous white light phase. These findings cannot be generalized: We could demonstrate that in the tropical plant Momordica charantia greening under white light was not affected by different temperature pretreatments during predarkening. The stimulating effect of a cold, predarkening period on greening is assumed to have ecological relevance.
Early wrong‐way response occurs in orthogravitropism of maize roots treated with lithium
Authors: Millet Bernard , Pickard Barbara G.
Published: July 2007

Millet, B. and Pickard, B. G. 1988. Early wrong‐way response occurs in orthogravitropism of maize roots treated with lithium. ‐ Physiol. Plant. 72: 555–559.

Application of lithium ions to tips of roots of Zea mays L. cv. Silver Queen shifts the direction of initial orthogravitropic curvature from downward to upward. The production of this putatively incidental perturbation of orthogravitropic bending kinetics by a pharmacological agent might provide insight into both ortho‐ and plagiogravitro‐pism. Additionally, the protocol of the experiments bears on recent claims that mucilage external to the root cap plays an essential role in gravitropism. External mucilage was removed before roots were stimulated, yet they reached about 50 degrees gravitropic curvature in an hour.
Effects of drought on host and endophyte development in mycorrhizal soybeans in relation to water use and phosphate uptake
Authors: Bethlenfalvay Gabor J. , Brown Milford S. , Ames Robert N. , Thomas Richard S.
Published: July 2007

Bethlenfalvay, G. J., Brown, M. S., Ames, R. N. and Thomas, R. S. 1988. Effects of drought on host and endophyte development in mycorrhizal soybeans in relation to water use and phosphate uptake. ‐ Physiol. Plant. 72: 565–571.

Soybean [Glycine max (L.) Merr.] plants were grown in pot cultures and inoculated with the vesicular‐arbuscular mycorrhizal (VAM) fungus Glomus mosseae (Nicol. & Gerd.) Gerd. and Trappe or provided with P fertilizer (non‐VAM plants). After an initial growth period (21 days), plants were exposed to cycles of severe, moderate or no drought stress over a subsequent 28‐day period by rewatering at soil water potentials of ‐1.0, ‐0.3 or ‐0.05 MPa. Dry weights of VAM plants were greater at severe stress and smaller at no stress than those of non‐VAM plants. Phosphorus fertilization was applied to produce VAM and non‐VAM plants of the same size at moderate stress. Root and leaf P concentrations were higher in non‐VAM plants at all stress levels. All plants were stressed to permanent wilting prior to harvest. VAM plants had lower soil moisture content at harvest than non‐VAM plants. Colonization of roots by G. mosseae did not vary with stress, but the biomass and length of the extraradical mycelium was greater in severely stressed than in non‐stressed plants. Growth enhancement of VAM plants relative to P‐fertilized non‐VAM plants under severe stress was attributed to increased uptake of water as well as to more efficient P uptake. The ability of VAM plants to deplete soil water to a greater extent than non‐VAM plants suggests lower permanent wilting potentials for the former.
Short‐term responses of phloem transport to mechanical perturbation
Authors: Jaeger C. H. , Goeschl J. D. , Magnuson C. E. , Fares Y. , Strain B. R.
Published: July 2007

Jaeger, C. H., Goeschl, J. D., Magnuson, C. E., Fares, Y. and Strain, B. R. 1988. Short‐term responses of phloem transport to mechanical perturbation. ‐ Physiol. Plant. 72: 588–594.

Phloem transport was monitored using a continuous stream of11CO2‐labelled air administered to one leaf while gamma detectors measured11C activity at intervals along the stem. The effect of gentle, non‐injurious mechanical perturbation on phloem transport was tested in cotton (Gossypium hirsutumL. cv. Stoneville 213). Mechanical stimuli such as shaking, localized vibration and gentle massage were applied while the plants were at isotope equilibrium. Localized phloem blockages were observed within 1–2 min of the stimuli. The blockages lasted from 6–55 min and full recovery of transport required 20–175 min. The effect of preconditioning to mechanical perturbation on phloem transport was tested in bush beans (Phaseolus vulgarisL. cv. Cherokee Bush). Preconditioning of a bean seedling to gentle stem massage resulted in a shorter blockage response and quicker transport recovery period when the seedling was massaged during a11C tracer experiment compared to a control seedling. These results indicate that measurements of phloem transport on recently disturbed plants will probably show depressed phloem transport velocities. Measurements should be made after at least a 24‐h disturbance‐free recovery period.
Measurement of light within thin plant tissues with fiber optic microprobes
Authors: Vogelmann Thomas C. , Knapp Alan K. , McClean Therese M. , Smith William K.
Published: July 2007

Vogelmann, T. C., Knapp, A. K., McClean, T. M. and Smith, W. K. 1988. Measurement of light within thin plant tissues with fiber optic microprobes. ‐ Physiol. Plant. 72: 623–630.

The measurement of light with fiber optic microprobes has been extended to thin (200–300 μm) plant tissue samples. To test the method, light measurements were made in thin aqueous films and paradermal sections from 10‐day‐old etiolatedCucurbita pepoL. cv. Fordhook cotyledons. The measurements obtained were highly reproducible. Paradermal sections of spongy mesophyll that were irradiated with collimated light scattered light more effectively than the palisade layer of intact cotyledons. These results demonstrate that different plant tissues have different light scattering characteristics. The successful extension of the fiber optic microprobe technique to thin systems makes it possible to examine the optical properties of different cell layers within leaves and other plant organs.
Metabolism and translocation of nitrogen in two Lolium perenne populations with contrasting rates of mature leaf respiration and yield
Authors: Barneix Atilio J. , Cooper H. David , Stulen Ineke , Lambers Hans
Published: July 2007

Barneix, A. J., Cooper, H. D., Stulen, I. and Lambers, H. 1988. Metabolism and translocation of nitrogen in two Lolium perenne populations with contrasting rates of mature leaf respiration and yield. ‐ Physiol. Plant. 72: 631–636.

Several aspects of nitrogen metabolism and transport were investigated to determine whether these processes could account for the observed differences in the dark respiration rate of mature leaves between two populations of Lolium perenne L. cv. S23: GL72 ‐ a slow respiring, high growth rate line, and cv. GL66 ‐ a fast respiring, low growth rate line.

No differences were found in total nitrogen or soluble protein concentrations between the populations, but GL72 showed a higher concentration of soluble amino acids, accounted for mainly by increases in the amounts of asparagine and glutamine. There were no differences in the glutamine synthetase (EC 6.3.1.2) or nitrate reductase (EC 1.6.6.1) activities between populations, but the fast respiring GL66 line showed higher glutamate dehydrogenase (EC 1.4.1.3) and peroxidase (EC 1.11.1.7) activities than GL72. The protein turnover rate, determined from 3H disappearance from leaves labelled with [3H]‐acetic anhydride, appeared to be larger in GL66, but the difference was not significant and could not account for the differences in respiration rate.

The apparent extent of 15N cycling between roots and shoots was low in Lolium compared to other grass species, and there were no differences between the two populations.

It is concluded that the differences in dark respiration rate are not due to differences in demand for ATP by nitrogen assimilatory processes, but may be related to faster leaf senescence in the GL66 population.
A reassessment of glycolysis and gluconeogenesis in higher plants
Authors: Sung Shi‐Jean S. , Xu Dian‐Peng , Galloway Cynthia M. , Black Clanton C.
Published: July 2007

Sung, S.‐J. S., Xu, D.‐P., Galloway, C. M. and Black, C. C., Jr. 1988. A reassessment of glycolysis and gluconeogenesis in higher plants. ‐ Physiol. Plant. 72: 650–654.

Sucrose is the starting point of glycolysis and end point of gluconeogenesis in higher plants. During both glycolysis and gluconeogenesis alternative enzymes are present at various steps to carry out parallel pathways; alternatives are available for utilizing nucleotide triphosphates and pyrophosphate; fructose 2,6‐bisphosphate serves as a strong internal regulator; and plants use these cytoplasmic alternatives as they develop and as their environments change.
The physiological basis of seed dormancy in Avena fatua. IX. Characterization of two dormancy states
Authors: Adkins Stephen W. , Simpson Graham M.
Published: July 2007

The dormancy‐breaking effect of several known germination promoters was studied in 9 genetically pure lines of Avena fatua L. during a period of controlled after‐ripening. Changes in the germination response show at least two dormancy states in the caryopses of these lines. The first state is overcome by a short period of after‐ripening and is insensitive to nitrate and azide, while the second state is more persistent and is sensitive to nitrate and azide. Both states are sensitive to gibberellic acid (OA,) and ethanol. In the most dormant lines a third ethanol‐insensitive dormancy state is present. The duration of both major dormancy states was related to several environmental factors influencing plant growth and seed storage. Duration was increased in caryopses produced from plants matured under low temperatures (15°C) and decreased in caryopses produced from plants matured under high temperatures (25°C). Duration was increased in caryopses after‐ripened under low temperatures (4°C) and decreased in caryopses after‐ripened under high temperatures (45°C). Dehulling the seeds prior to after‐ripening reduced the duration of both major dormancy states. The multiple state dormancy system and its environmentally induced plasticity are discussed with reference to previous explanations of the dormancy mechanism in wild oats.
Exogenous application of abscisic acid or triadimefon affects the recovery of Zea mays seedlings from heat shock
Authors: Bonham‐Smith P. C. , Kapoor M. , Bewley J. D.
Published: July 2007

Maize seedlings (Zea mays L. cv. DK 246) grown for 1–4 days in the presence of abscisic acid (ABA) or triadimefon (a fungicide) demonstrated an enhanced ability to withstand the effects of a 3‐h sub‐lethal (40°C) or lethal (45°C) heat shock. Both the ABA and triadimefon treatments were applied solely to the roots of seedlings; however, the ability to withstand a heat shock was induced in both the root and the shoot. The level of protection provided by these agents was dependent upon the time that plants were exposed to them; prolonged exposure reduced tolerance to subsequent stress.
Photosynthetic light acclimation in fully developed leaves of the juvenile and adult life phases of Hedera helix
Authors: Bauer Helmut , Thöni Wolfgang
Published: July 2007

The aim of this study was to investigate the extent to which fully developed leaves of Hedera helix L. are capable of acclimating to new light conditions and how this ability is determined by the life phase of the plant. To this end juvenile and adult plants were transferred from a low (L) to a moderately high (H) light regime and vice versa and changes of photosynthetic gas exchange, RuBP carboxylase (EC 4.1.1.39) activity and specific anatomy were monitored in leaves that were fully developed prior to the transfer.

Immediately after transfer from L to H there was a decrease in the rate of net photosynthesis (Fn). This photoinhibition was particularly pronounced in leaves of the adult life phase. Fn recovered after 10 to 20 days at H, and 40 to 65 days after transfer the rate exceeded that of control plants by about 20% in leaves of the adult life phase and by about 50% in leaves of the juvenile life phase. If H plants were transferred to L, Fn had declined only slightly after 30 to 40 days and regained its initial level within a few days, when the plants were returned to the original high light regime.

The increased rates of Fn per unit leaf area in leaves transferred from L to H were associated with higher light levels necessary to saturate Fn, higher carboxylation efficiencies, higher contents of soluble protein and higher activities of RuBP carboxylase, whereas the quantum yield did not change. Although fully differentiated before transfer, the leaves had formed a further cell layer in the palisade parenchyma. Related to leaf volume there was no increase in Fn.

Our results indicate that in the adult life phase of ivy phenotypie light acclimation occurs mainly during leaf development, whereas in juvenile plants fully expanded leaves still possess a rather wide modulativc acclimation plasticity.
The effects of external electric field on the electron transport system of spinach chloroplasts
Authors: Hsu Ban‐Dar , Jang Yuh‐Ren , Lee Jee‐Yau
Published: July 2007

Since the thylakoid membranes of an active chloroplast are constantly exposed to the electric fields generated by the electron transport system inside the membranes, we have studied the effects of pretreating chloroplasts of spinach (Spinacia oleracea L.) leaves with an external AC (alternating current) electric field on their electron transport system. It was found that a few minutes electric field pretreatment (333 V cm‐1 across chloroplast samples), especially at low frequency, irreversibly inhibited the activity of photosystem II (PSII), but under certain conditions, stimulated that of photosystem I (PSI). From the measurements of fluorescence from PSII, we ascribe the inhibition to a lesion close to its reaction center P680, leading to increased dissipation of excitation energy to heat. The effect on PSI was investigated by the reduction of its reaction center, P700 by various artificial donors. We suggest that the stimulative effect can be attributed to a positive shift of the surface charge density of thylakoid membranes that brings about an increase in the accessibility of exogenous electronegative donors.
Indoleacetic acid, abscisic acid and phenolic substances during development of hazel leaves
Authors: Rodríguez Ana , Cañal María Jesús , Tamés Ricardo Sánchez
Published: July 2007

The levels of indoleacetic acid (IAA), abscisic acid (ABA) and phenolic substances were measured monthly in leaves of hazel (Corylus avellana L. cv. Negreta) in different stages of development from April till abscission in November. IAA and ABA were quantified by flame ionization detector gas‐chromatography (GLC), and the total phenolic content by a colorimetric technique. During spring, IAA levels were the highest, coinciding with the greatest expansion of the leaves; after which IAA gradually decreased as the leaves became older, although minor increases were observed in July‐August and November. The ABA level in hazel leaves was low throughout the period of leaf existence, with a maximum in July and a second increase in November, coinciding with the last month in which hazel bears leaves. The phenols of the neutral fraction showed a minimum in May and a pronounced increase in June, remaining at this level during summer and decreasing in November. The acid and alkaline fractions showed a maximum in August, which could be related to the decrease in the growth rate of leaves. The residual fraction remained at a relatively low level until September, increasing rapidly in October and November.
Thansplasmalemma redox reactions and ion transport in photosynthetic and heterotrophic plant cells
Authors: Ivankina Natalija G. , Novak Vasilij A.
Published: July 2007

Extracellular ferricyanide reduction, NADH and ferrocyanide oxidation were investigated by spectrophotometrical method on photosynthetic freshwater plants (Elodea canadensis Rich., Vallisneria spiralis L., Nitella flexilis L.) and heterotrophic tissues (roots of Triticum vulgare L., Hordeum vulgare L., Zea mays L., Pisum sativum L., Avena sativa L., Allium sativa L., Allium cepa L.). All species had ferricyanide reductase activity. The roots of land plants also carried out extracellular oxidation of NADH and ferrocyanide in contrast to leaves of the freshwater plants. External NADH stimulated ferricyanide reductase activity, but only with those objects that had external NADH oxidase activity. In all species ferricyanide decreased the membrane potential (MP), decreased the membrane resistance measured at a fixed current and inhibited K+ influx measured by flame photometry. The factors affecting ferricyanide reductase activity also influenced the inhibitory effect of ferricyanide on the MP and K+ transport. These results demonstrate a connection between transport, electrogenic and redox functions of the plasmalemma.
The link between the electrogenic and redox functions of the plasmalemma and the energy metabolism of the cell
Authors: Novak Vasilij A. , Ivankina Natalija G. , Morokova Elena A. , Miclashevich Antonina I.
Published: July 2007

A dependence of the plasmalemma redox activity, determined by the reduction of external electron acceptors (ferricyanide, nitro‐blue tetrazolium), on the energy state of the cell, which was modified by light conditions or introduction of glucose into the media, was shown on leaves of Elodea canadensis Rich. Glucose (10 mM) and light (40 W m‐2) caused hyperpolarization of the membrane potential and stimulated the redox activity of the plasmalemma. 3‐(3,4‐Dichlorophenyl)‐1,1‐dimethylurea (DCMU) completely inhibited the light activation of electrogenic and redox functions of the plasmalemma. The light saturation intensity for membrane potential and ferricyanide reductase activity was 10–30% of the light saturation of photosynthesis. Membrane potential, K+ transport and plasmalemma redox activity changed in parallel in response to light and darkness and when DCMU was added. Ferricyanide reductase activity is suggested to be a simple parameter for characterizing the energy state of the cell. The functional significance of the light‐induced hyperpolarization of the membrane potential is discussed.
Long‐term follow‐up for reconstruction of strictures of the fossa navicularis with a single technique
Authors: Virasoro Ramón , Eltahawy Ehab A. , Jordan Gerald H.
Published: July 2007

In a paper from the USA the authors describe their experience with the ventral transverse skin island flap elevated on a dartos fascia flap for reconstructing strictures of the fossa navicularis. They found it to be effective, with good functional and aesthetic results.

OBJECTIVE

To retrospectively review our experience with the ventral transverse skin island elevated on a dartos fascia flap.

PATIENTS AND METHODS

In all, 45 patients were consecutively operated by the senior author using this technique from March 1987 to January 2006. The files of 35 patients were assessed for the study. Success was defined as a patent urethral calibre of ≥16 F that did not require further procedures. Follow‐up consisted of, endoscopy with calibration, office visits, and telephone calls. This procedure was described in 1987 by Jordan. The overall outcome as well as indications after the follow‐up period are presented.

RESULTS

The overall success rate was 83% with a mean long‐term follow‐up of 10.2 years. All of the patients with a non‐lichen sclerosus (LS)/balanitis xerotica obliterans (BXO) diagnosis had excellent results (23/23) with a mean follow‐up of 10.2 years. LS/BXO recurred at the fossa or meatus in six of 12 patients. Seventeen patients (48%) were lost to follow‐up, and three patients (9%) died from other causes.

CONCLUSIONS

The ventral transverse penile skin island flap has proven to be effective, reliable, reproducible, and with good functional and aesthetic results in all fossa navicularis strictures with the exception of those strictures resulting from LS/BXO.
The Fictions of Autonomous Invention: Accumulation by Dispossession, Commodification and Life Patents in Canada
Authors: Prudham Scott
Published: July 2007

Abstract:  In 2002 the Canadian Supreme Court ruled to deny Harvard College a whole organism patent over the oncomouse. In 2004, the same court ruled that Canadian farmer Percy Schmeiser had violated Monsanto patents covering GM canola. Both decisions rejected whole organism patents, running counter to US precedents. Yet both, nevertheless, consolidate private claims to life as patentable inventions, and critics claim, with some support from Justices in the Schmeiser case, that patents over genes amount to de facto patents over whole organisms. In this paper I argue these cases are broadly consistent with the notion of accumulation by dispossession as a means to expand the scale and scope of capital accumulation via so‐called ‘extra‐economic’ means. As such, I examine the cases as privatizations, but also as relational moments in the commodification of nature. However, in hoping to unpack and fill out this notion of the extra‐economic, as well as to critically examine the necessarily incomplete character of commodification as a tendency, I look to the ways in which judges and interested activists deliberate over the economic, legal, ecological, ethical, and even metaphysical arguments and representations required to uphold discrete genes, processes, and whole organisms as inventions.
Differential Impact of Repression on Social Movements: Christian Organizations and Liberation Theology in South Korea (1972–1979)*
Authors: Chang Paul Y. , Kim Byung‐Soo
Published: July 2007

During the height of authoritarianism in South Korea (1972–1979), Christian activists challenged the state along two dimensions. First, protesting Christians formed formal social movement organizations to better garner the resources to sustain their social movement. Second, they waged a discursive battle that challenged the legitimizing rhetoric of the state. By 1979, Christians developed a social movement industry involving the network of formal organizations as well as systematizing their rhetoric of protest in the guise of a Korean liberation theology; Minjung Theology. Drawing upon archival data and social movement theory, this study traces the rise and development of both the Christian social movement industry and Minjung Theology. We find that the emergence and evolution of mobilizing structures and movement frames were influenced by the state's repressive apparatuses and legitimizing rhetoric, respectively. Likewise, Christians’ attempts to mobilize and challenge the legitimizing rhetoric of the state further contributed to the closing of the political opportunity structure. This study empirically verifies recent theoretical work emphasizing the importance of considering the differential impact of repression on various components of a social movement.
It's the Message, Not the Messenger: The Declining Significance of Black–White Contact in a “Colorblind” Society*
Authors: O’Brien Eileen , Korgen Kathleen Odell
Published: July 2007

We argue that due to the modern‐day prevalence of colorblind racism, the impact of interracial contact on whites’ racial consciousness is limited. By comparing two qualitative data sets of white antiracists and whites who have a close black friend, we find there are a good number of whites for whom relationships with people of color are not the prime impetus for becoming antiracist. Whites often bracket out their black friends from their limited understandings of racism, and white antiracists often adopt progressive ideologies from other whites. Even when interracial contact is part of white antiracists’ experiences, it often is but one small step in aprocess of sensitizationto an antiracist counterideology. The bearers of this antiracist ideology (the “message”) may or may not be persons of color (the assumed “messengers”) so we explore a variety of ways that this “message” takes hold (or not) among whites. While not discounting contact theory altogether, we make plain that colorblindness is a major factor limiting its explanatory power. We conclude by discussing the methodological and theoretical implications of our findings for sociological race relations research.
Family Structure Pathways and Academic Disadvantage among Adolescents in Stepfamilies*
Authors: Tillman Kathryn Harker
Published: July 2007

Using National Longitudinal Study of Adolescent Health (Add Health) data, this research documents the prevalence of the different stepfamily forms in which American adolescents live, examines the family structure pathways through which adolescents traveled to arrive at their current family form, and explores the effects of these pathways on grades, school‐related behavior, and college expectations (N = 13,988). Compared to those who have always lived with both biological parents, youth in pathways including divorce/separation or a nonunion birth experience significantly lower academic outcomes, while those whose pathways include parental death do not. Specific effects vary, however, according to the outcome examined. For example, the combination of divorce/separation and movement into the least common of family forms is associated with particularly poor GPA outcomes. Divorce/separation is also more detrimental than nonunion birth for college expectations, particularly when coupled with a transition into a stepfamily based on cohabitation. Divorce/separation and nonunion birth have similar, negative effects on school behavior problems. Overall, results indicate that living in a stepfamily does not benefit youth, and can in some ways disadvantage them, even compared to their peers in single‐mother families. This is especially the case if youth transition into a stepfamily following a combination of stressful family experiences. These findings underscore the importance of examining family effects from a longitudinal perspective.
Effects of Rural and Urban Population Dynamics and National Development on Deforestation in Less‐Developed Countries, 1990–2000*
Authors: Jorgenson Andrew K. , Burns Thomas J.
Published: July 2007

While prior research and theorization establish connections between population growth and environmental degradation, there is a relative paucity of research on what particularaspectsof population dynamics are most closely associated with specific types of degradation. Considering all less‐developed countries for which data are available, using Ordinary Least Square (OLS) regression we generate quantitative, cross‐national models for rates of deforestation in the last decade of the twentieth century. The opposite effects of rural and urban population dynamics are of particular concern. While both influence deforestation rates, the effects of rural population change tend to be more profound and more robust. We discuss these findings in light of theoretical work about circular migration and rural encroachment. In addition, we examine the impact of economic development on deforestation while controlling for political and social welfare variables. Findings suggest a trend toward rapidly increasing rates of deforestation in the least‐developed countries. We conclude with a discussion of how rural–urban population dynamics, in combination with other aspects of national development, affect the natural environment, particularly in light of an increasingly interconnected world economy.
From Opportunity Insight to Opportunity Intention: The Importance of Person–Situation Learning Match
Authors: Dimov Dimo
Published: July 2007

Within the context of opportunity development as a learning process, this paper explores the intentionality that drives the early stages of this process, from the initial occurrence of an idea to its further exploration and elaboration by a potential entrepreneur. It establishes that the specific situations that induce opportunity insights also affect the roles that individuals’ prior knowledge and learning approaches play for the formation of opportunity intentions. The likelihood of acting on their initial opportunity insights depends not only on how much prior knowledge individuals have of the opportunity domain, but also on whether their learning style matches the situation at hand. The results from an experiment show that domain–specific knowledge enables action when there is a person–situation match and impedes it when such a match is lacking.