bluuebunny/crossref_metadata_2025 huggingface dataset:
Glyphosate resistance in four different populations of Lolium rigidum is associated with reduced translocation of glyphosate to meristematic zones
Authors: Wakelin A M , Lorraine‐Colwill D F , Preston C
Published: November 2004

Weed populations with resistance to glyphosate have evolved over the last 7 years, since the discovery of the first glyphosate‐resistant populations of Lolium rigidum in Australia. Four populations of L. rigidum from cropping, horticultural and viticultural areas in New South Wales and South Australia were tested for resistance to glyphosate by dose–response experiments. All populations required considerably more glyphosate to achieve 50% control compared with a known susceptible population, indicating they were resistant to glyphosate. Translocation of glyphosate within these resistant populations was examined by following the movement of radiolabelled glyphosate applied to a mature leaf. All resistant plants translocated significantly more herbicide to the tip of the treated leaf than did susceptible plants. Susceptible plants translocated twice as much herbicide to the stem meristematic portion of the plant compared with resistant plants. These different translocation patterns suggest an association between glyphosate resistance in L. rigidum and the ability of glyphosate to accumulate in the shoot meristem.
How do salinity and water stress affect transport of water, assimilates and ions to tomato fruits?
Authors: Plaut Zvi , Grava Auraham , Yehezkel Chana , Matan Eli
Published: November 2004

The study was conducted in order to determine whether water stress affects the accumulation of dry matter in tomato fruits similarly to salinity, and whether the increase in fruit dry matter content is solely a result of the decrease in water content. Although the rate of water transport to tomato fruits decreased throughout the entire season in saline water irrigated plants, accumulation rates of dry matter increased significantly. Phloem water transport contributed 80–85% of the total water transport in the control and water‐stressed plants, and over 90% under salinity. The concentration of organic compounds in the phloem sap was increased by 40% by salinity. The rate of ions transported via the xylem was also significantly increased by salinity, but their contribution to fruit osmotic adjustment was less. The rate of fruit transpiration was also markedly reduced by salinity. Water stress also decreased the rate of water transport to the tomato fruit and increased the rate of dry matter accumulation, but much less than salinity. The similar changes, 10–15%, indicate that the rise in dry matter accumulation was a result of the decrease in water transport. Other parameters such as fruit transpiration rates, phloem and xylem sap concentration, relative transport via phloem and xylem, solutes contributing to osmotic adjustment of fruits and leaves, were only slightly affected by water stress. The smaller response of these parameters to water stress as compared to salinity could not be attributed to milder stress intensity, as leaf water potential was found to be more negative. Measuring fruit growth of girdled trusses, in which phloem flow was inactive, and comparing it with ungirdled trusses validated the mechanistic model. The relative transport of girdled as compared to ungirdled fruits resembled the calculated values of xylem transport.
Role of thylakoid Ndh complex and peroxidase in the protection against photo‐oxidative stress: fluorescence and enzyme activities in wild‐type and ndhF‐deficient tobacco
Authors: Martín Mercedes , Casano Leonardo M. , Zapata José M. , Guéra Alfredo , Del Campo Eva M. , Schmitz‐Linneweber Christian , Maier Rainer M. , Sabater Bartolomé
Published: November 2004

An Ndh‐deficient mutant of tobacco (Nicotiana tabacum cv. Petit Havana) was prepared by disrupting the ndhF gene in a transplastomic approach. The mutant (ΔndhF) showed 10% of the Ndh complex activity (EC 1.6.5.3) and 8% of the NDH‐F polypeptide of that of non‐transformed plants. However, in ΔndhF, NDH‐A, another Ndh polypeptide, was still present at 50% of the level in non‐transformed plants. ΔndhF tobacco showed higher sensitivity than non‐transformed plants to photo‐oxidative stress (as judged by chlorophyll bleaching) caused by increased light intensity and paraquat applications. These photo‐oxidative treatments increased the amount and activity of the Ndh complex, thylakoid peroxidase, post‐illumination chlorophyll fluorescence and non‐photochemical quenching (NPQ) of chlorophyll fluorescence in non‐transformed but not in ΔndhF tobacco. Highly stressed non‐transformed plants showed a rapid post‐rise decline of chlorophyll fluorescence, probably indicating a re‐oxidation of reduced plastoquinone. The results indicate that, in normal plants, the Ndh complex and thylakoid peroxidase (EC 1.11.1.7) provide and remove electrons, respectively, to balance the redox level of the intermediates of cyclic electron transport. In this way, they optimize the generation of the transmembrane H+ gradient of thylakoids and, as a consequence, increase the NPQ and the protection against photo‐oxidative stress.
Mechanism for deactivation of Rubisco under moderate heat stress
Authors: Salvucci Michael E. , Crafts‐Brandner Steven J.
Published: November 2004

Photosynthesis is particularly sensitive to direct inhibition by heat stress. This inhibition is closely associated with the inactivation of ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco). To develop a more complete understanding of the mechanism of inactivation of Rubisco under moderate heat stress, various aspects of the process were examined both in vivo and in vitro. Experiments with isolated Rubisco revealed that the rate of synthesis of the catalytic misfire product, xylulose‐1,5‐bisphosphate, increased with temperature. Activated Rubisco, produced by reaction with activase at a control temperature of 25°C or by incubation with high CO2, deactivated when the temperature of the reaction exceeded temperatures that were equivalent to the optimum for activase adenosine triphosphatase (ATPase) activity. Measurements of the activation state of Rubisco in cotton and tobacco leaves showed that Rubisco inactivated within 7 s of imposing a heat stress. Thus, elevated temperature had an opposite effect on the two processes that ultimately determine the activation state of Rubisco, decreasing activase activity but stimulating the catalytic misfire reaction that inactivates Rubisco. These data support a mechanism for the inactivation of Rubisco at high temperature involving an inability of activase to overcome the inherently faster rates of Rubisco inactivation. That the net effect of elevated temperatures on Rubisco activation is similar both in vivo and under controlled conditions in vitro argues for a direct effect of temperature on the activation of Rubisco by activase and against the proposal that the deactivation of Rubisco under moderate heat stress is a secondary consequence of perturbations in the thylakoid membrane.
Washing of cord blood grafts after thawing: high cell recovery using an automated and closed system*
Authors: Rodríguez L. , Azqueta C. , Azzalin S. , García J. , Querol S.
Published: November 2004

Background and Objectives  Cord blood (CB) progenitor cells are an alternative source of haematopoietic stem cells for bone marrow reconstitution. The critical importance of cell dose in the clinical outcome has motivated the need to develop techniques aimed at reducing cell losses and increasing reproducibility. This aim of this study was to evaluate an automated CB washing protocol of thawed cord blood units using the Sepax device.

Materials and Methods  After an initial 1 : 1 dilution using a dextran/albumin‐containing buffer, the cells were washed in order to obtain a final product ready for transplantation. The automatic method was compared with the conventional manual washing procedure. Blood samples were taken after thawing and after washing. The processing time, viability and mean recovery of nucleated cells (TNC) and progenitors were determined.

Results  The automatic procedure resulted in a median recovery of 93% CD34+ cells and 89% TNC; no significant differences were observed between methods. In addition, median viability, as assessed by annexin V and 7‐aminoactinomycin D (7‐AAD), was 98% and 94%, respectively, within CD34+ cells.

Conclusions  The automatic washing method described is as effective as the manual method in terms of viability and progenitor cells recovery, but faster and easier for the operators to perform. Overall, our data suggest that the automatic method is safe and suitable for the routine washing of thawed CB grafts in the clinic.
Inactivation of Gram‐negative and Gram‐positive bacteria in red cell concentrates using INACTINE PEN110 chemistry
Authors: Zavizion B. , Serebryanik D. , Chapman J. , Alford B. , Purmal A.
Published: November 2004

Background and Objectives  The risk of transfusion‐transmitted bacterial infections as a result of the presence of bacteria in blood is one of the major concerns in transfusion medicine. The purpose of this study was to investigate whether bacteria inoculated into red blood cell concentrates can be inactivated by the INACTINE PEN110 pathogen‐reduction process. Four bacterial species were chosen for the study: anaerobic Gram‐positive Clostridium perfringens and Propionibacterium acnes, known to be transfusion‐transmitted; and two Gram‐negative species, Acinetobacter johnsonii and Acinetobacter lwoffii, recently reported to be a common cause of transfusion‐associated infections in Europe.

Materials and Methods  Identical units of leucoreduced red cell concentrates were inoculated with A. johnsonii, A. lwoffii, C. perfringens, or P. acnes. The 4 °C control units were put on storage immediately after receiving the spike. The test units were subjected to PEN110 treatment and then stored. The bacterial titre in all units was monitored during a 6‐week storage period.

Results  The PEN110 inactivation of all tested bacterial strains was time‐ and titre‐dependent. For A. johnsonii and A. lwoffii, no viable bacteria were detected in the units spiked with up to 104 colony‐forming units (CFU)/ml and treated with PEN110. For red cell units spiked with 104−105 CFU/ml of C. perfringens and P. acnes, no viable bacteria were detected in the units treated with PEN110. In control units, there was a gradual decrease in A. johnsonii, A. lwoffii and C. perfringens titres during cold storage, while P. acnes titres remained stable.

Conclusions  The PEN110 pathogen‐reduction process was demonstrated to inactivate high titres of A. johnsonii, A. lwoffii, C. perfringens and P. acnes in red cell concentrates.
Leucodepletion leads to component‐like storage stability of whole blood – suggesting its homologous use?
Authors: Picker S. M. , Stürner S. S. , Oustianskaja L. , Gathof B. S.
Published: November 2004

Background and Objectives  Leucodepleted whole blood (LWB) is already widely used for autologous donations and could also be appropriate for certain instances of allogeneic transfusion provided that storage quality can be preserved at component‐like levels.

Materials and Methods  Sixteen units of whole blood (WB), donated by healthy volunteers into CPDA‐1 according to German guidelines, were leucofiltered prestorage and stored for up to 49 days. Unfiltered WB in CPDA‐1 (UFWB, n = 16) and filtered red blood cells in SAGM (RCC, n = 14) served as controls. Several haematological, biochemical and coagulatory quality parameters were determined at designated time‐points during storage.

Results  Apart from significant differences (P < 0·05) in haematocrit (56·2 ± 3·6 vs. 37·9 ± 3·9%), and in the plasma concentrations of free haemoglobin (93·1 ± 37·8 vs. 57·8 ± 24·3 g/dl), K+ (38·9 ± 5·3 vs. 31·5 ± 4·3 mm) and ATP (2·7 ± 0·2 vs. 1·6 ± 0·4 µmol/g haemoglobin), with higher levels detected in RCC, no remarkable differences (P > 0·05) were observed regarding haemolysis (0·23 ± 0·07% vs. 0·31 ± 0·13) and pH value (6·63 ± 0·03 vs. 6·62 ± 0·02) between RCC and LWB at the end of storage. Lack of leucodepletion manifested in significantly (P < 0·05) higher rates of haemolysis (0·44 ± 0·21%), free haemoglobin (89·6 ± 43·5 g/dl) and lower pH values (6·56 ± 0·04). During 42 days of LWB storage, sufficient amounts (% of the initial mean value) were observed with stable (factor XI, 97·5 ± 15·0) and labile (factor V, 92·9 ± 18·0; factor VIII, 69·2 ± 17·1) clotting factors and inhibitors (antithrombin III 88·9 ± 9·5), without any signs of activated coagulation.

Conclusions  Our data indicate that the quality of LWB is comparable to that of components during 42 days of storage. Thus, LWB could be an interesting option for using to facilitate and economize the blood supply, especially for surgical or trauma patients.
Chagas’ disease: application of TESA‐blot in inconclusive sera from a Brazilian blood bank
Authors: Silveira‐Lacerda E. P. , Silva A. G. , Junior S. F. , Souza M. A. , Kesper N. , Botelho‐Filho A. , Umezawa E. S.
Published: November 2004

Background and Objectives  The procedure used for screening Trypanosoma cruzi‐infected blood donors by using two serological techniques has frequently led to discordant results. The TESA‐blot, a confirmatory test for Chagas’ disease, was applied in a survey of inconclusive sera from a Brazilian blood bank.

Materials and Methods  Four hundred and forty‐eight sera, obtained from blood donors at the HRU‐Fundação Hemominas, were tested by using the TESA‐blot assay, a Western blotting method. Of these 448 sera, 348 had previously been determined as inconclusive for Chagas’ disease owing to discordance between the indirect immunofluorescence assay (IFA) and the enzyme‐linked immunosorbent assay (ELISA).

Results  The TESA‐blot was positive for 2·87% (10/348) of the inconclusive sera, and 100% positive and negative for the sera from chagasic (n = 50) and non‐chagasic (n = 50) donors, respectively.

Conclusions  Our results clearly indicate the need to improve the diagnosis of Chagas’ disease in blood banks by using new confirmatory diagnostic test(s). The TESA‐blot, a new test with trypomastigote fractions of the T. cruzi Y strain, has made new approaches to the confirmation of Chagas’ disease possible.
VASCULAR AND ANTI‐OXIDANT ACTIONS OF FLAVONOLS AND FLAVONES
Authors: Woodman Owen L , Chan Elsa CH
Published: November 2004

1. Flavonols and flavones are plant‐derived polyphenolic compounds that are commonly consumed in the diet. Epidemiological studies indicating that high dietary intake of flavonols reduces the risk of mortality due to coronary heart disease have provoked interest in the mechanism of this cardioprotective effect.

2. We have investigated the structure–activity relationships of a range of flavonols and flavones with regard to their vascular relaxant and anti‐oxidant activity. In rat isolated thoracic aorta, the synthetic flavonol 3′,4′‐dihydroxyflavonol (DiOHF) was found to be a significantly more potent vasorelaxant than the naturally occurring compounds chrysin, apigenin, luteolin, quercetin and fisetin. Similarly, DiOHF was significantly more potent than those compounds in the inhibition of calcium‐induced contraction of the rat aorta.

3. 3′,4′‐Dihydroxyflavonol was also found to significantly inhibit superoxide radical generation in a cell‐free system in the presence of xanthine/xanthine oxidase or by rat isolated aorta in the presence of NADPH. In the presence of oxidant stress generated by pyrogallol or xanthine/xanthine oxidase, endothelium‐dependent relaxation of rat aortic rings was impaired. 3′,4′‐Dihydroxyflavonol was able to significantly improve endothelium‐dependent relaxation in the presence of those oxygen radical generators.

4. In addition, DiOHF was found to significantly improve dilatation in the rat hindquarters vasculature after exposure to ischaemia and reperfusion. 3′,4′‐Dihydroxyflavonol was found to be equally effective whether applied before ischaemia or during ischaemia just before reperfusion.

5. In conclusion, DiOHF is an effective vasodilator and anti‐oxidant that is able to prevent vascular reperfusion injury. We suggest that DiOHF may be useful as an adjunct to thrombolytic therapy in the management of reperfusion injury.
ARTERIAL STIFFNESS, ENDOTHELIAL FUNCTION AND NOVEL PHARMACOLOGICAL APPROACHES
Authors: Wilkinson Ian B , McEniery Carmel M
Published: November 2004

1. Despite over half a century of intensive research, cardiovascular disease remains the leading cause of death world wide. Nevertheless, a number of risk factors for cardiovascular disease have been identified, such as hypertension and serum cholesterol, and therapies targeting such factors are effective in reducing cardiovascular and total mortality. Arterial stiffness is an additional independent risk factor for cardiovascular disease and strategies aimed at lowering arterial stiffness may be effective in reducing cardiovascular risk. However, in order to exploit fully the therapeutic potential of this approach, it is necessary first to understand the physiological and pathophysiological factors regulating the stiffness of the large arteries.

2. Until recently, stiffness was thought to depend largely upon structural components within the arterial wall, such as elastin and collagen and the distending pressure. However, we now recognize that arterial smooth muscle also regulates vessel stiffness and that a number of locally derived and circulating factors, including nitric oxide (NO), endothelin‐1 and the natriuretic peptides, contribute to the short‐term or functional regulation of large artery stiffness. Changes in the balance between these factors and, in particular, a reduction in NO production may well explain why conditions such as hypercholesterolaemia and diabetes are themselves associated with arterial stiffening before the development of manifest atherosclerosis.

3. The importance of smooth muscle in regulating arterial stiffness suggests that direct pharmacological manipulation of stiffness may be possible, thus providing novel therapeutic strategies to reduce cardiovascular risk. Furthermore, differences in the effect of existing drugs on larger artery stiffness may explain, in part, why some drugs produce better clinical outcomes than others.
INTERACTIONS BETWEEN δ OPIOID RECEPTORS AND α2A‐ADRENOCEPTORS
Authors: Rios Carl , Gomes Ivone , Devi Lakshmi A
Published: November 2004

1. Several studies have reported functional interactions between different subtypes of opioid and α2A‐adrenoceptors in the induction of spinal cord analgesia. The mechanisms underlying this phenomenon are not well characterized. We propose that direct receptor–receptor associations could account for some of the observed functional interactions. In the present study, we examined the presence of δ opioid receptors and α2A‐adrenoceptors in interacting complexes and the functional implications of such interactions on receptor activity.

2. Using the proximity based bioluminescence resonance energy transfer (BRET) assay, we found that the δ opioid receptors and α2A‐adrenoceptors are in close enough proximity (< 100 Å) in live cells that can foster physical interactions.

3. Using coimmunoprecipitation of differentially epitope‐tagged receptors, we found that δ opiate receptors exist in interacting complexes with α2A‐adrenoceptors in heterologous cells.

4. Finally, using receptor activity mediated neurite outgrowth in Neuro 2A cells as a physiological readout, we found that interactions between δ opiate receptors and α2A‐adrenoceptors have functional consequences. The expression of α2A‐adrenoceptors is sufficient to promote δ opiate receptor‐mediated neurite outgrowth, suggesting that the presence of inactive α2A‐adrenoceptors can enhance δ opiate receptor‐mediated signalling.

5. Taken together, these findings suggest that modulation of receptor function as a result of physical associations between δ opiate receptors and α2A‐adrenoceptors may account for the observed synergy between opiate and adrenergic agonists in spinal analgesia.
CIRCADIAN CHANGES IN THE QT VARIABILITY INDEX IN THE BEAGLE DOG
Authors: Nolan Emily R , Girand Michael , Bailie Marc , Yeragani Vikram Kumar
Published: November 2004

1. QT variability is a non‐invasive marker of cardiac repolarization lability and a higher QT variability is associated with sudden death. No data exist as to the circadian fluctuations in QT variability and the QT variability index (QTvi) in the canine. The purpose of the present investigation was to explore QT interval variability over 24 h in the healthy dog.

2. Continuous lead II electrocardiogram and blood pressure data were collected for 24 h from three beagles instrumented with radiotelemetry devices. The mean heart rate (HR), detrended HR variance, mean QT interval and detrended QT variance were calculated from the instantaneous HR and QT time series of 1024 points (256 s), as described previously, and a normalized QTvi was derived.

3. The dog has a diurnal pattern of QTvi similar to healthy humans. Both dogs and humans exhibit a significantly higher QTvi during active waking hours, with more negative values during deep sleep.

4. These findings suggest QTvi may serve as an additional non‐invasive tool to assess ventricular repolarization lability in dogs in relation to any conditions or drugs that are known to be associated with increased cardiac mortality.
CAN WE DIFFERENTIATE BETWEEN AIRWAY AND VASCULAR SMOOTH MUSCLE?
Authors: Fernandes Darren J , McConville John F , Stewart Alastair G , Kalinichenko Vladimir , Solway Julian
Published: November 2004

1. Airway smooth muscle (ASM) has recently been termed the ‘frustrated’ cell of the lung given that contraction of ASM has no proven useful physiological function in adults and yet is indelibly associated with pathological conditions by virtue of its unwanted airflow‐limiting actions in asthma. In contrast, pulmonary vascular smooth muscle contraction plays an essential role in the control of blood flow through the lung.

2. Little is known of the differences in phenotype between human ASM and pulmonary vascular smooth muscle (VSM) tissues, but differences in contractile protein and transcription factor expression and regulation of contractile protein promoter activity have been documented. Similarly, the embryological signals in mice required for differentiation of ASM versus pulmonary VSM are distinct.

3. Bronchoconstriction in asthma is currently treated with β2‐adrenoceptor agonists, which relax contracted ASM cells. An additional approach may be to use gene therapy to render ASM unable to contract (via disruption of their contractile apparatus organization).

4. Application of ASM‐specific gene therapies would rely on minimal actions on other lung smooth muscle tissues, including pulmonary and bronchial vascular smooth muscle. The combination of mRNA analysis of laser‐captured microdissected tissue with in situ immunohistochemical staining for protein should be very useful in terms of being able to characterize definitively the differences in mRNA and protein expression between the smooth muscle species of the lung. Any discovery of an ASM‐selective target could provide a novel lead for ASM‐directed anti‐asthma therapy.
EFFECTS OF GLUTAMATE TRANSPORT SUBSTRATES AND GLUTAMATE RECEPTOR LIGANDS ON THE ACTIVITY OF Na+/K+‐ATPase IN BRAIN TISSUE IN VITRO
Authors: Nanitsos Ellas K , Acosta Gabriela B , Saihara Yukiko , Stanton David , Liao Lee P , Shin Jae W , Rae Caroline , Balcar Vladimir J
Published: November 2004

1. It has been suggested that Na+/K+‐ATPase and Na+‐dependent glutamate transport (GluT) are tightly linked in brain tissue. In the present study, we have investigated Na+/K+‐ATPase activity using Rb+ uptake by ‘minislices’ (prisms) of the cerebral cortex. This preparation preserves the morphology of neurons, synapses and astrocytes and is known to possess potent GluT that has been well characterized. Uptake of Rb+ was determined by estimating Rb+ in aqueous extracts of the minislices, using atomic absorption spectroscopy.

2. We determined the potencies of several known substrates/inhibitors of GluT, such as l‐trans‐pyrrolidine‐2,4‐dicarboxylate (LtPDC), dl‐threo‐3‐benzyloxyaspartic acid, (2S,3S,4R)‐2‐(carboxycyclopropyl)‐glycine (L‐CCG III) and l‐anti,endo‐3,4‐methanopyrrolidine dicarboxylic acid, as inhibitors of [3H]‐l‐glutamate uptake by cortical prisms. In addition, we established the susceptibility of GluT, measured as [3H]‐l‐glutamate uptake in brain cortical prisms, to the inhibition of Na+/K+‐ATPase by ouabain. Then, we tested the hypothesis that the Na+/K+‐ATPase (measured as Rb+ uptake) can respond to changes in the activity of GluT produced by using GluT substrates as GluT‐specific pharmacological tools.

3. The Na+/K+‐ATPase inhibitor ouabain completely blocked Rb+ uptake (IC50 = 17 µmol/L), but it also potently inhibited a fraction of GluT (approximately 50% of [3H]‐l‐glutamate uptake was eliminated; IC50 < 1 µmol/L).

4. None of the most commonly used GluT substrates and inhibitors, such as l‐aspartate, d‐aspartate, L‐CCG III and LtPDC (all at 500 µmol/L), produced any significant changes in Rb+ uptake.

5. The N‐methyl‐d‐aspartate (NMDA) receptor agonists (R,S)‐(tetrazol‐5‐yl)‐glycine and NMDA decreased Rb+ uptake in a manner compatible with their known neurotoxic actions.

6. None of the agonists or antagonists for any of the other major classes of glutamate receptors caused significant changes in Rb+ uptake.

7. We conclude that, even if a subpopulation of glutamate transporters in the rat cerebral cortex may be intimately linked to a fraction of Na+/K+‐ATPase, it is not possible, under the present experimental conditions, to detect regulation of Na+/K+‐ATPase by GluT.
MULTIPLE LEVELS OF SENSORY INTEGRATION IN THE INTRINSIC SENSORY NEURONS OF THE ENTERIC NERVOUS SYSTEM
Authors: Bertrand Paul P , Thomas Evan A
Published: November 2004

1. The enteric nervous system (ENS) is present in the wall of the gastrointestinal tract and contains all the functional classes of neuron required for complete reflex arcs. One of the most important and intriguing classes of neuron is that responsive to sensory stimuli: sensory neurons with cell bodies intrinsic to the ENS.

2. These neurons have three outstanding and interrelated features: (i) reciprocal connections with each other; (ii) a slow excitatory post‐synaptic potential (EPSP) resulting from high‐speed firing in other sensory neurons; and (iii) a large after‐hyperpolarizing potential (AHP) at the soma. Slow EPSP depolarize the cell body, generate action potentials (APs) and reduce the AHP. Conversely, the AHP limits the firing rate and, hence, reduces transmission of slow EPSP.

3. Processing of sensory information starts at the input terminals as different patterns of APs depending on the sensory modality and recent sensory history. At the soma, the ability to fire APs and, hence, drive outputs is also strongly determined by the recent firing history of the neuron (through the AHP) and network activity (through the slow EPSP). Positive feedback within the population of intrinsic sensory neurons means that the network is able to drive outputs well beyond the duration of the stimuli that triggered them.

4. Thus, sensory input and subsequent reflex generation are integrated over several hierarchical levels within the network on intrinsic sensory neurons.
CURRENCY MARKET CONTAGION IN THE ASIA‐PACIFIC REGION
Authors: DUNGEY MARDI , FRY RENÉE , MARTIN VANCE L.
Published: November 2004

During the East Asian currency crisis of 1997–98 the potential transmission of the crisis to developed markets such as Japan, Australia and New Zealand, was of considerable policy concern. Potential channels consist of anticipated movements stemming from common factors, spillovers and contagion. The empirical results show that the transmission of volatility in the East‐Asian currency markets to the developed markets in the region is not due to contagion, but rather attributed to common world factors. Spillovers have a minor role in the case of Japan and to a lesser degree, Australia.
ENVIRONMENTAL EFFICIENCY OF THE AUSTRALIAN IRRIGATION INDUSTRY IN TREATING SALT EMISSIONS
Authors: GANG LIU , FELMINGHAM BRUCE
Published: November 2004

In this paper, a stochastic translog production function frontier is specified to estimate the input‐oriented technical efficiency of 11 major Australian irrigation schemes. The analysis is applied to a panel data set including the years 1998/1999, 1999/2000 and 2000/2001. The environmental efficiency of each sampled irrigation scheme in relation to treating salt emissions is measured. These EE measures are based on estimates of technical efficiency. The potential reduction of the environmentally detrimental salt emissions resulting from the improvement of environmental inefficiency is estimated. The study indicates that the sampled schemes operated at an average of 80.4% (1998/1999), 89.9% (1999/2000) to 95% (2000/2001) of full environmental efficiency. The potential contraction of salt emission is substantial. The paper also reveals that there is a wide range of EE scores in each year suggesting differences in the management performance of the salt emission problem across individual schemes.
Developing the Concept of Transparency for Use in Supply Relationships
Authors: Lamming Richard , Caldwell Nigel , Harrison Deborah
Published: November 2004

Management concern surrounding the supply of goods and services from business to business, and the related attempts to understand the phenomena observed therein, appears to rest upon a broad range of incompatible perspectives, from political science (often limited to considerations of power) to the logistical (akin to manipulation of a great, benign but dynamic jigsaw puzzle). It appears that all perspectives abrade against the difficulties of exchanging information, knowledge and innovation within the relationships between buying and selling organizations and the apparent chronic systemic inefficiency that transactions often represent in this context. This article addresses these concerns, exploring the concept of transparency and the developments necessary for it to be useful in exchanging sensitive information and tacit knowledge in supply relationships. Our central concern is how the understanding of transparency and its commercial importance may change when it is expressed as a manageable element of the relationship between two organizations rather than as a general property of a broader system (e.g. a supply network, industrial sub‐sector, geographical cluster) and what utility this differentiation might hold for managers. The conclusion to the article, and the implication for managers, is that transparency might indeed be created and usefully managed within supply relationships but that it would differ fundamentally in meaning from previously posited concepts, with the same name, in different contexts.
Demographic and Attitudinal Correlates of Employee Satisfaction with an ESOP
Authors: Hallock Daniel E. , Salazar Ronald J. , Venneman Sandy
Published: November 2004

A firm's adoption of an employee stock ownership plan (ESOP) has been hypothesized to increase employee productivity. Resulting employee productivity is hypothesized to improve firm profitability and thus ultimately improve stock performance. Most studies to date have tested potential relationships between the mere presence of an ESOP and changes in employee productivity and firm profitability. Few studies have attempted to identify the variables that are associated with employee satisfaction with an ESOP. In order to maximize the productivity gains associated with the adoption of an ESOP, researchers must first identify the relationships and variables most likely to positively affect employee attitudes and subsequently their satisfaction toward an ESOP. The purpose of this paper is to identify the demographic and attitudinal correlates of employee satisfaction with an ESOP. This exploration will provide a more substantive foundation for future research efforts in the area. Correlation and regression results indicated that employees' perceived influence on decision‐making, perceived pay equity and perceived influence on stock performance, when examined separately, were each significant correlates of ESOP satisfaction. When combined with the modelled employee demographics in a step‐wise regression model, only employees' perceived influence on stock performance, perceived influence on decision‐making and age explained a statistically significant amount of variance in ESOP satisfaction.
The Role of Shocks in Employee Turnover*
Authors: Morrell Kevin , Loan‐Clarke John , Wilkinson Adrian
Published: November 2004

This paper reports the findings from a recent study of nurse leavers at eight large hospitals in the National Health Service (NHS) of England and Wales. The study develops and extends an influential theory of employee turnover by describing how for some leavers a single, jarring event or shock triggers the decision to quit. By elaborating on the nature of shocks for this sample of 352 nurse leavers, the paper allows for improved understanding of nursing turnover and thus offers an example of relevant management research. The analysis of shock illustrates how conventional research methodologies can lead to a distorted picture of turnover. This has wider implications, both for any organization wishing to manage turnover effectively and for future research. The paper adds to the limited body of empirical analysis on actual leavers, thereby contributing to an ongoing methodological debate concerning the use of proxy variables. By highlighting flaws in the dominant methodology used to study turnover, the paper offers an example of management research that is also rigorous, and thus ‘pragmatic’.
Should I Stay or Should I Go? Explaining Turnover Intentions with Organizational Identification and Job Satisfaction*
Authors: Van Dick Rolf , Christ Oliver , Stellmacher Jost , Wagner Ulrich , Ahlswede Oliver , Grubba Cornelia , Hauptmeier Martin , Höhfeld Corinna , Moltzen Kai , Tissington Patrick A.
Published: November 2004

The social identity approach is a powerful theoretical framework for the understanding of individuals' behaviour. The main argument is that individuals think and act on behalf of the group they belong to because this group membership adds to their social identity, which partly determines one's self‐esteem. In the organizational world, social identity and self‐categorization theories state that a strong organizational identification is associated with low turnover intentions. Because identification is the more general perception of shared fate between employee and organization, we propose that the relationship between identification and turnover will be mediated by job satisfaction as the more specific evaluation of one's task and working conditions. In four samples we found organizational identification feeding into job satisfaction, which in turn predicts turnover intentions.
ARTHUR LEWIS's CONTRIBUTION TO DEVELOPMENT THINKING AND POLICY
Authors: RANIS GUSTAV
Published: November 2004

Arthur Lewis's seminal 1954 paper and its emphasis on dualism appeared at a time when neither the work of Keynes and Harrod–Domar nor the later neoclassical production function of Solow seemed relevant for developing countries. As a consequence, his model, rooted in the classical tradition, plus its many extensions, generated an extensive literature at the center of development theory. The approach also encountered increasingly strong criticism, some of the ‘red herring’ variety. Some, spearheaded by neoclassical microeconomists like Rosenzweig, raised serious challenges and focused especially on its labor market assumptions. This paper reviews this landscape and asks what theoretical or policy relevance the Lewis model retains for today's developing countries.
INSTITUTIONS AND POLITICS IN A LEWIS‐TYPE GROWTH MODEL
Authors: MOSLEY PAUL
Published: November 2004

The paper examines the impact of politics and institutions on growth in the light of Lewis's writings. The basic approach adopted is that the accumulation of ‘capitalist surplus’ can be threatened for political reasons. If the oppressed are likely to rebel against poor living standards associated with economic development with unlimited supplies of labour, it is sensible for governments to invest in political and institutional devices which will prevent the threat of such disturbances. We call such investments a ‘social efficiency wage premium’ and find that growth, across a sample of 58 countries for the period between 1980 and 2001, is significantly associated with the measures a country takes to reduce its political vulnerability. The paper concludes that investments of a country's surplus in measures to reduce political vulnerability are well warranted.
Truth and Robustness in Cross‐country Growth Regressions*
Authors: Hoover Kevin D. , Perez Stephen J.
Published: November 2004

We re‐examine studies of cross‐country growth regressions by Levine and Renelt (American Economic Review, Vol. 82, 1992, pp. 942–963) and Sala‐i‐Martin (American Economic Review, Vol. 87, 1997a, pp. 178–183; Economics Department, Columbia, University, 1997b). In a realistic Monte Carlo experiment, their variants of Edward Leamer's extreme‐bounds analysis are compared with a cross‐sectional version of the general‐to‐specific search methodology associated with the LSE approach to econometrics. Levine and Renelt's method has low size and low power, while Sala‐i‐Martin's method has high size and high power. The general‐to‐specific methodology is shown to have a near nominal size and high power. Sala‐i‐Martin's method and the general‐to‐specific method are then applied to the actual data from Sala‐i‐Martin's original study.
Inter‐industry Wage Differences and Individual Heterogeneity*
Authors: Carruth Alan , Collier William , Dickerson Andy
Published: November 2004

Two well‐established findings are apparent in the analyses of individual wage determination: cross‐section wage equations can account for less than half of the variance in earnings and there are large and persistent inter‐industry wage differentials. We explore these two empirical regularities using longitudinal data from the British Household Panel Survey (BHPS). We show that around 90% of the variation in earnings can be explained by observed and unobserved individual characteristics. However, small – but statistically significant – industry wage premia do remain, and there is also a role for a rich set of job and workplace controls.
Do Wages Rise or Fall Following Merger?*
Authors: Conyon Martin J. , Girma Sourafel , Thompson Steve , Wright Peter W.
Published: November 2004

This paper provides a systematic empirical analysis of the effects of merger and acquisition activity on profitability and firm‐level employee remuneration in the UK, using a specially constructed database for the period 1979–91. It finds that both profitability and wages rise following acquisition, and firms that merge within the same industry division experience larger increases in profitability and pay their workers higher wages than those engaged in unrelated acquisitions; i.e. in part, the result of an increase in the efficiency with which labour is used following related acquisition.
Tests for Stationarity in Series with Endogenously Determined Structural Change*
Authors: Harvey David I. , Mills Terence C.
Published: November 2004

We consider tests of the null hypothesis of stationarity against a unit root alternative, when the series is subject to structural change at an unknown point in time. Three extant tests are reviewed which allow for an endogenously determined instantaneous structural break, and a related fourth procedure is introduced. We further propose tests which permit the structural change to be gradual rather than instantaneous, allowing the null hypothesis to be stationarity about a smooth transition in linear trend. The size and power properties of the tests are investigated, and the tests are applied to four economic time series.
Integration of metrical and tonal organization in melody perception1
Authors: ABE JUN‐ICHI , OKADA AKIHIRO
Published: November 2004

Abstract: The interplay between metrical and tonal organization in melody perception was investigated. Ten musicians listened to five variations of excerpts from each of 12 melodies and judged the keys and rhythms. Original‐condition trials retained the original temporal and pitch patterns of the melodies. Either the temporal or the pitch pattern was shifted in phase by one or two notes and recombined with the other pattern to create the temporal‐shift and the pitch‐shift conditions. The results showed that the listeners’ key interpretation varied between the temporal‐shift conditions, but their metrical interpretation did not vary between the pitch‐shift conditions. These results suggest that the metrical organization was not as influenced by the pitch shifts as the tonal organization was influenced by the temporal shifts. In the process of melody perception, tonal organization is executed using the predictive output of metrical organization.
Perceiving emotion in children's songs across age and culture1
Authors: ADACHI MAYUMI , TREHUB SANDRA E. , ABE JUN‐ICHI
Published: November 2004

Abstract: We explored children's and adults’ ability to perceive the emotional intent of sung performances by Canadian children who were 8–10 years old. Experiment 1 revealed that Canadian listeners were more accurate on happy renditions than on sad renditions of songs and on skilled (“good”) than on unskilled (“ordinary”) performances. Moreover, children's accuracy was greater than that of adults. In Experiment 2, Japanese children and adults with limited comprehension of spoken English successfully perceived the expressive intentions of Canadian children, but they were more accurate on sad renditions than on happy renditions. Japanese children performed better than adults, but only on the sad renditions. Moreover, the accuracy of Japanese children and adults was greater for skilled than for unskilled singers, but only on happy renditions. Finally, expressive cues in children's sung performances were predictive of accuracy regardless of the age or the cultural background of listeners (Experiment 3).
Recognition of emotion in Japanese, Western, and Hindustani music by Japanese listeners1
Authors: BALKWILL LAURA‐LEE , THOMPSON WILLIAM FORDE , MATSUNAGA RIE
Published: November 2004

Abstract: Japanese listeners rated the expression of joy, anger and sadness in Japanese, Western, and Hindustani music. Excerpts were also rated for tempo, loudness, and complexity. Listeners were sensitive to the intended emotion in music from all three cultures, and judgments of emotion were related to judgments of acoustic cues. High ratings of joy were associated with music judged to be fast in tempo and melodically simple. High ratings of sadness were associated with music judged to be slow in tempo and melodically complex. High ratings of anger were associated with music judged to be louder and more complex. The findings suggest that listeners are sensitive to emotion in familiar and unfamiliar music, and this sensitivity is associated with the perception of acoustic cues that transcend cultural boundaries.
Structure and Dynamics of the Golgi Complex at 15 °C: Low Temperature Induces the Formation of Golgi‐Derived Tubules
Authors: Martínez‐Alonso Emma , Egea Gustavo , Ballesta José , Martínez‐Menárguez José A.
Published: November 2004

Immunofluorescence and cryoimmunoelectron microscopy were used to examine the morphologic and functional effects on the Golgi complex when protein transport is blocked at the ERGIC (endoplasmic reticulum‐Golgi intermediate compartment) in HeLa cells incubated at low temperature (15 °C). At this temperature, the Golgi complex showed long tubules containing resident glycosylation enzymes but not matrix proteins. These Golgi‐derived tubules also lacked anterograde (VSV‐G) or retrograde (Shiga toxin) cargo. The formation of tubules was dependent on both energy and intact microtubule and actin cytoskeletons. Conversely, brefeldin A or cycloheximide treatments did not modify the appearance. When examined at the electron microscope, Golgi stacks were long and curved and appeared connected to tubules immunoreactive to galactosyltransferase antibodies but devoid of Golgi matrix proteins. Strikingly, COPI proteins moved from membranes to the cytosol at 15 °C, which could explain the formation of tubules.
The Cargo in Vacuolar Storage Protein Transport Vesicles is Stratified
Authors: Wenzel Dirk , Schauermann Gaby , Lüpke Anke von , Hinz Giselbert
Published: November 2004

Developing pea seeds contain two functionally distinct vacuoles – lytic vacuoles and protein storage vacuoles (PSV). The Golgi apparatus of these cells has to discriminate between proteins destined for these vacuolar compartments. Whereas it is known that sorting into the lytic vacuole is performed via the conserved clathrin‐coated vesicle pathway, sorting of proteins into the protein storage vacuole remains enigmatic. In developing pea cotyledons, the major storage proteins are sorted via ‘dense vesicles’. In this report we examined the sorting of a minor protein of the protein storage vacuole, the sucrose‐binding‐protein homolog (SBP), along the secretory pathway employing immunoelectron microscopy on cryosectioned pea cotyledons. SBP follows the same vesicular route into the PSV as the main storage proteins legumin and vicilin, via the dense‐vesicles. Furthermore, legumin and SBP are sorted together into the same dense vesicle population at the stack. Although soluble cargo proteins of the dense vesicles, they show a stratified distribution in the lumen of the dense vesicles. Whereas the legumin label is equally distributed across the lumen, the SBP label is concentrated at the membrane of the vesicle. This observation is discussed with respect to a putative receptor‐mediated sorting of the proteins into the dense vesicles.
Starvation Triggers the Delivery of the Endoplasmic Reticulum to the Vacuole via Autophagy in Yeast
Authors: Hamasaki Maho , Noda Takeshi , Baba Misuzu , Ohsumi Yoshinori
Published: November 2004

Autophagy is a survival mechanism necessary for eukaryotic cells to overcome nutritionally challenged environments. When autophagy is triggered, cells degrade nonselectively engulfed cytosolic proteins and free ribosomes that are evenly distributed throughout the cytoplasm. The resulting pool of free amino acids is used to sustain processes crucial for survival. Here we characterize an autophagic degradation of the endoplasmic reticulum (ER) under starvation conditions in addition to cytosolic protein degradation. Golgi membrane protein was not engulfed by the autophagosome under the same conditions, indicating that the uptake of ER by autophagosome was the specific event. Although the ER exists in a network structure that is mutually connected and resides predominantly around the nucleus and beneath the plasma membrane, most of autophagosome engulfed ER. The extent of the ER uptake by autophagy was nearly identical to that of the soluble cytosolic proteins. This phenomenon was explained by the appearance of fragmented ER membrane structures in almost all autophagosomes. Furthermore, ER dynamism is required for this process: ER uptake by autophagosomes occurs in an actin‐dependent manner.
Covert Operations of Uropathogenic Escherichia coli within the Urinary Tract
Authors: Bower Jean M. , Eto Danelle S. , Mulvey Matthew A.
Published: November 2004

Entry into host cells is required for many bacterial pathogens to effectively disseminate within a host, avoid immune detection and cause disease. In recent years, many ostensibly extracellular bacteria have been shown to act as opportunistic intracellular pathogens. Among these are strains of uropathogenic Escherichia coli (UPEC), the primary causative agents of urinary tract infections (UTIs). UPEC are able to transiently invade, survive and multiply within the host cells and tissues constituting the urinary tract. Invasion of host cells by UPEC is promoted independently by distinct virulence factors, including cytotoxic necrotizing factor, Afa/Dr adhesins, and type 1 pili. Here we review the diverse mechanisms and consequences of host cell invasion by UPEC, focusing also on the impact of these processes on the persistence and recurrence of UTIs.