bluuebunny/crossref_metadata_2025 huggingface dataset:
A structural model of agonist binding to the α3β4 neuronal nicotinic receptor
Authors: Costa Valeria , Nistri Andrea , Cavalli Andrea , Carloni Paolo
Published: October 2003

(α3)2(β4)3 is the most abundant type of neuronal nicotinic ACh receptor (nAChR) mediating cholinergic actions on the autonomic nervous system. Studies to refine or devise drugs selectively acting on (α3)2(β4)3 receptors would benefit from a detailed description of the hitherto unclear agonist‐binding domain.

The present study reports a three‐dimensional model for the ligand‐binding domain (LBD) of this receptor either in its unoccupied or agonist‐bound conformation. The receptor model was based on the structure of the acetylcholine‐binding protein (AChBP), and was obtained using molecular modelling techniques.

ACh, nicotine and cytisine (full agonists), muscarine (a selective agonist of muscarinic ACh receptors) and the allosteric modulator eserine were docked into the binding pockets of the receptor model. Simulated agonist–receptor complexes were compared with the agonist‐binding complex of the AChBP, as well as of the (α4)2(β2)3 type of nAChR, which is the commonest in the brain.

Agonist docking identified discrete amino‐acid residues of the β subunits important for pharmacological selectivity of nAChRs. The predicted affinity of muscarine for the nAChR was low, suggesting the present model to be suitable for effective discrimination of nicotinic agonist binding versus nonselective cholinergic binding. Furthermore, the current model outlined a potential binding site for the allosteric modulator eserine, the site of action of which has remained elusive.

The present LBD model of the receptor in its free state provides a novel structural framework to interpret experimental observations and a useful template for future investigations to develop (α3)2(β4)3‐selective ligands.

British Journal of Pharmacology (2003) 140, 921–931. doi:10.1038/sj.bjp.0705498
The rabbit motilin receptor: molecular characterisation and pharmacology
Authors: Dass N B , Hill J , Muir A , Testa T , Wise A , Sanger G J
Published: October 2003

Following identification of the human motilin receptor, we isolated the rabbit orthologue by PCR amplification and found this to be 85% identical to the open reading frame of the human receptor. The protein encoded was 84% identical to the human polypeptide.

In HEK293T cells transfected with the rabbit receptor, motilin concentration‐dependently increased intracellular calcium mobilisation (pEC50=9.25). After transfection with Go1α, motilin similarly stimulated [35S]GTPγS binding (pEC50=8.87). Using both systems, similar values were obtained with the human receptor, with rank‐order potencies of motilin=[Nle13]‐motilin>erythromycin; ghrelin was ineffective.

In circular muscle preparations of rabbit gastric antrum, [Nle13]‐motilin 0.1–30 nM concentration‐dependently increased the amplitude of electrically‐evoked, neuronally‐mediated contractions (pEC50=8.3); higher concentrations increased the muscle tension (30–3000 nM). Both responses to [Nle13]‐motilin faded rapidly during its continual presence. Rat or human ghrelin 0.01–10 μM were without activity.

Erythromycin 30–3000 nM and 10 μM, respectively, increased neuronal activity and muscle tension in rabbit stomach. Unlike [Nle13]‐motilin, the increase in neuronal activity did not fade during continual presence of submaximally‐effective concentrations of erythromycin; some fade was observed at higher concentrations.

We conclude that the pharmacology of the rabbit motilin receptor is similar to the human orthologue and, when expressed as a recombinant, comparable to the native receptor. However, in terms of their ability to increase neuronal activity in rabbit stomach, [Nle13]‐motilin and erythromycin are distinguished by different response kinetics, reflecting different rates of ligand degradation and/or interaction with the receptor.

British Journal of Pharmacology (2003) 140, 948–954. doi:10.1038/sj.bjp.0705505
WAY‐855 (3‐amino‐tricyclo[2.2.1.02.6]heptane‐1,3‐dicarboxylic acid): a novel, EAAT2‐preferring, nonsubstrate inhibitor of high‐affinity glutamate uptake
Authors: Dunlop John , Eliasof Scott , Stack Gary , McIlvain H Beal , Greenfield Alexander , Kowal Dianne , Petroski Robert , Carrick Tikva
Published: October 2003

The pharmacological profile of a novel glutamate transport inhibitor, WAY‐855 (3‐amino‐tricyclo[2.2.1.02.6]heptane‐1,3‐dicarboxylic acid), on the activity of the human forebrain glutamate transporters EAAT1, EAAT2 and EAAT3 expressed in stable mammalian cell lines and in Xenopus laevis oocytes is presented.

WAY‐855 inhibited glutamate uptake mediated by all three subtypes in a concentration‐dependent manner, with preferential inhibition of the CNS‐predominant EAAT2 subtype in both cells and oocytes. IC50 values for EAAT2 and EAAT3 inhibition in cells were 2.2 and 24.5 μM, respectively, while EAAT1 activity was inhibited by 50% at 100 μM (IC50 values determined in oocytes were 1.3 μM (EAAT2), 52.5 μM (EAAT3) and 125.9 μM (EAAT1)).

Application of WAY‐855 to EAAT‐expressing oocytes failed to induce a transporter current, and the compound failed to exchange with accumulated [3H]D‐aspartate in synaptosomes consistent with a nonsubstrate inhibitor. WAY‐855 inhibited D‐aspartate uptake into cortical synaptosomes by a competitive mechanism, and with similar potency to that observed for the cloned EAAT2.

WAY‐855 failed to agonise or antagonise ionotropic glutamate receptors in cultured hippocampal neurones, or the human metabotropic glutamate receptor subtype 4 expressed in a stable cell line.

WAY‐855 represents a novel structure in glutamate transporter pharmacology, and exploration of this structure might provide insights into the discrimination between EAAT2 and other EAAT subtypes.

British Journal of Pharmacology (2003) 140, 839–846. doi:10.1038/sj.bjp.0705509
Characterization of the role of endogenous cholecystokinin on the activity of the paraventricular nucleus of the hypothalamus in rats
Authors: Cano Victoria , Ezquerra Laura , Pilar Ramos M , Ruiz‐Gayo Mariano
Published: October 2003

Activation of the hypothalamic–pituitary–adrenal axis by fasting seems to involve cholecystokinin (CCK) receptors.

This work aims to characterize the role of endogenous CCK in the activity of the paraventricular nucleus (PVN) of the hypothalamus during food withdrawal. We investigated, by c‐Fos immunohistochemistry, the effect of CCK1 and CCK2 receptor antagonists (SR‐27,897 and L‐365,260, respectively) on c‐Fos levels expression induced by food deprivation.

Under our conditions, the number of cells expressing c‐Fos was reduced both by SR‐27,897 and L‐365,260 in food‐deprived rats.

To investigate the importance of glucose availability, we studied the effect of CCK receptor antagonists on c‐Fos synthesis induced by the glucose antimetabolite 2‐deoxyglucose. In these animals, only SR‐27,897 decreased c‐Fos expression in the PVN.

Our results indicate that the effect of CCK antagonists is mainly perceptible when glucose availability decreases, and suggest that CCK‐ergic inputs could drive the activity of the PVN under fasting/low glucose conditions.

British Journal of Pharmacology (2003) 140, 964–970. doi:10.1038/sj.bjp.0705513
Mechanisms underlying the inhibitory effects of tachykinin receptor antagonists on eosinophil recruitment in an allergic pleurisy model in mice
Authors: Alessandri Ana Letícia , Pinho Vanessa , Souza Danielle G , Castro Maria Salete de A , Klein André , Teixeira Mauro M
Published: October 2003

The activation of tachykinin NK receptors by neuropeptides may induce the recruitment of eosinophils in vivo. The aim of the present study was to investigate the effects and underlying mechanism(s) of the action of tachykinin receptor antagonists on eosinophil recruitment in a model of allergic pleurisy in mice.

Pretreatment of immunized mice with capsaicin partially prevented the recruitment of eosinophils after antigen challenge, suggesting the potential contribution of sensory nerves for the recruitment of eosinophils

Local (10–50 nmol per pleural cavity) or systemic (100–300 nmol per animal) pretreatment with the tachykinin NK1 receptor antagonist SR140333 prevented the recruitment of eosinophils induced by antigen challenge of immunized mice. Neither tachykinin NK2 nor NK3 receptor antagonists suppressed eosinophil recruitment.

Pretreatment with SR140333 failed to prevent the antigen‐induced increase of interleukin‐5 concentrations in the pleural cavity. Similarly, SR140333 failed to affect the bone marrow eosinophilia observed at 48 h after antigen challenge of immunized mice.

SR140333 induced a significant increase in the concentrations of antigen‐induced eotaxin at 6 h after challenge.

Antigen challenge of immunized mice induced a significant increase of Leucotriene B4 (LTB4) concentrations at 6 h after challenge. Pretreatment with SR140333 prevented the antigen‐induced increase of LTB4 concentrations.

Our data suggest an important role for NK1 receptor activation with consequent LTB4 release and eosinophil recruitment in a model of allergic pleurisy in the mouse. Tachykinins appear to be released mainly from peripheral endings of capsaicin‐sensitive sensory neurons and may act on mast cells to facilitate antigen‐driven release of LTB4.

British Journal of Pharmacology (2003) 140, 847–854. doi:10.1038/sj.bjp.0705515
Mechanisms of relaxation by urocortin in renal arteries from male and female rats
Authors: Sanz Elena , Monge Luis , Fernández Nuria , Climent Belén , Diéguez Godofredo , Garcia‐Villalón Angel Luis
Published: October 2003

Urocortin is a peptide recently identified, which is structurally related to the corticotropin‐releasing factor (CRF). To analyze the mechanisms that could be involved in its effect on renal arteries from male and female rats, the response to urocortin was studied in isolated segments, 2 mm long, of renal arteries from male and female rats.

In renal artery segments precontracted with endothelin‐1 (1 nM), urocortin (1 pM–10 nM) produced concentration‐dependent relaxation, which was similar in the arteries from male and female rats.

This relaxation was reduced by the antagonists of urocortin receptors astressin (1 μM) and α‐helical CRF(9–41) (1 μM) in arteries from both male and female rats.

In renal arteries from female rats, the relaxation to urocortin was reduced by the inhibitor of adenyl cyclase SQ22536 (300 μM), by 8‐bromo‐cyclic‐ADP‐ribose (cADPR; 30 μM), an antagonist of the endogenous activator of sarcoplasmic Ca2+ channel cADPR and by ryanodine (1 μM), which produces depletion of sarcoplasmic Ca2+.

In renal arteries from male rats, the relaxation to urocortin was increased by ryanodine, and was not modified by SQ22536 or 8‐bromo‐cADPR.

These results suggest that the mechanisms involved in the relaxation to urocortin in renal arteries differ between female and male rats. In female rats, this relaxation may be mediated by the production of cyclic AMP (cAMP), synthesis of cADPR and release of sarcoplasmic Ca2+, whereas in male rats it is not mediated by cAMP.

British Journal of Pharmacology (2003) 140, 1003–1007. doi:10.1038/sj.bjp.0705516
Pentobarbitone modulates calcium transients in axons and synaptic boutons of hippocampal CA1 neurons
Authors: Baudoux Sylvie , Empson Ruth M , Richards Christopher D
Published: October 2003

Although barbiturates, like other general anaesthetics, depress excitatory synaptic transmission in the central nervous system (CNS), the underlying cellular mechanisms remain unresolved. They may increase the likelihood that an action potential will fail to invade every branch of the axonal arbour, thereby decreasing the synaptic drive to the postsynaptic neurons. Alternatively, they may inhibit calcium entry into the presynaptic terminals, thus reducing transmitter release.

To resolve these issues, we have used two‐photon microscopy to monitor calcium transients evoked by action potentials in axons, axonal varicosities (synaptic boutons) and fine axon collaterals of hippocampal CA1 neurons.

Pentobarbitone (75–300 μM) did not block the invasion of the axonal arbour or the synaptic boutons, but it did reduce the amplitude of the calcium transients recorded from the axons in a concentration‐dependent manner. At 150 μM, pentobarbitone reduced the transients to 78±4% of the control.

Pentobarbitone depressed the calcium transients recorded from the synaptic boutons in a concentration‐dependent manner. When 150 μM pentobarbitone was applied, the calcium transients recorded from the boutons were 53±3% of the control. This concentration of pentobarbitone also reduced the amplitude and frequency of the spontaneous excitatory postsynaptic potentials to 54±4 and 42±17% of the control, respectively.

The local anaesthetic procaine (500 μM) had no significant effect on action potential invasion of axon collaterals, even though it reduced the action potential amplitude by 25%.

This data are consistent with the notion that the pentobarbitone‐induced depression of presynaptic calcium transients contributes to its depressant effect on excitatory synaptic transmission in the CNS.

British Journal of Pharmacology (2003) 140, 971–979. doi:10.1038/sj.bjp.0705519
FK506 potentiates NGF‐induced neurite outgrowth via the Ras/Raf/MAP kinase pathway
Authors: Price Raymond D , Yamaji Takayuki , Matsuoka Nobuya
Published: October 2003

Nerve growth factor (NGF) and other members of the neurotrophin family are critical for the survival and differentiation of neurons within the peripheral and central nervous systems.

Neurophilin ligands, including FK506, potentiate NGF‐induced neurite outgrowth in several experimental models, although the mechanism of this potentiation is unclear.

Therefore, we tested which signaling pathways were involved in FK506‐potentiated neurite outgrowth in SH‐SY5Y neuroblastoma cells using specific pharmacological inhibitors of various signaling molecules.

Inhibitors of Ras (lovastatin), Raf (GW5074), or MAP kinase (PD98059 and U0126) blocked FK506 activity, as did inhibitors of phospholipase C (U73122) and phosphatidylinositol 3′ kinase (LY294002).

Protein kinase C inhibitors (Go6983 and Ro31‐8220) slightly but significantly inhibited neurite outgrowth, whereas inhibitors of p38 MAPK (SB203580) or c‐Jun N‐terminal kinase (SP600125) had no effect.

These data suggest that FK506 potentiates neurite outgrowth through the Ras/Raf/MAP kinase signaling pathway downstream of phospholipase C and phosphatidylinositol 3′ kinase.

British Journal of Pharmacology (2003) 140, 825–829. doi:10.1038/sj.bjp.0705522
Purification of lysozyme from other hen's‐egg‐white proteins using metal‐affinity precipitation
Authors: Roy Ipsita , Rao Mukkavilli V. S. , Gupta Munishwar N.
Published: October 2003

It was found that the presence of 5 mM Cu2+caused precipitation of protein present in hen's egg white to a large extent. About 85% of lysozyme activity remained in the supernatant and the enzyme was purified by approx. 13‐fold. A further gel‐filtration step on Sephadex G‐75 resulted in an overall yield of 80% for the enzyme with 655‐fold purification, and showed a single band on SDS/PAGE.
Mammalian cell production and purification of progenipoietin, a dual‐agonist chimaeric haematopoietic growth factor
Authors: Wood David C. , Mathis Karl J. , Joy William D. , Minnerly John C. , Pegg Lyle E. , Welply Joseph K.
Published: October 2003

One member of the progenipoietin (ProGP) family of engineered proteins, ProGP‐2, is a chimaeric dual cytokine receptor agonist, expressed in mammalian cells, that stimulates both human fetal liver tyrosine kinase‐3 (Flt3) and the granulocyte‐colony‐stimulating‐factor (G‐CSF) receptor. The production of ProGP‐2 on a small and large scale using either anti‐(Flt3 ligand) antibody‐affinity chromatography, or a combination of (NH4)2SO4 fractionation, anion‐exchange chromatography, hydrophobic‐interaction chromatography and preparative reverse‐phase chromatography is described. ProGP‐2 was produced in hollow‐fibre reactors containing stably transfected NS0 cells. The productivity of ProGP‐2 was initially high, but was found to decrease 3–4‐fold over time. When the yield of ProGP‐2 decreased, the combination of three conventional chromatography steps was required to meet protein purity similar to that achieved by the anti‐(Flt3 ligand) chromatography method. In addition, a protease activity was observed in conditioned media from the hollow‐fibre reactors that resulted in increased degradation of ProGP‐2 that was removed by hydrophobic‐interaction chromatography at higher pH. Together the results demonstrated a method for production and purification of ProGP‐2 for additional studies on its haematopoietic activity.
Measurement of NADH concentration in normal and malignant human tissues from breast and oral cavity
Authors: Uppal Abha , Gupta Pradeep Kumar
Published: October 2003

We report measurements of the concentration of NADH from malignant and non‐malignant sites of tissues resected from patients suffering from cancer of the breast or oral cavity. The concentration of NADH was found to be significantly higher in malignant breast‐tissue sites as compared with normal breast tissue, whereas the opposite result was obtained with malignant and normal tissues from the oral cavity. These results confirm the inferences made previously, from spectroscopic studies, and are consistent with other biochemical measurements reported in breast and oral cavity tissues.
Inhibitor studies of isopentenyl pyrophosphate biosynthesis in suspension cultures of the yew Taxus chinensis var. mairei
Authors: Wang Yan‐Dong , Yuan Ying‐Jin , Lu Ming , Wu Jin‐Chuan , Jiang Jian‐Lan
Published: October 2003

Some metabolic inhibitors, mevastatin (MVS), chlorocholine chloride (CCC), sodium pyrophosphate (NaPP) and d,l‐glyceraldehyde (DLG), were respectively added into the suspension cultures of the yew Taxus chinensis var. mairei at the late phase of cell growth to study isopentenyl pyrophosphate (IPP) biosynthesis. The content of total taxanes decreased in the cases of MVS, NaPP and DLG addition, regardless of the inhibitor concentration, whereas it increased in the case of CCC addition. It was thus presumed that a mevalonate pathway might exist in IPP biosynthesis at the late growth phase of Taxus cells and that some IPP might transfer from the cytoplasm to the plastids. This presumption was also confirmed by analysing the effects of the inhibitors on taxane content. It was further demonstrated that IPP in the biosynthesis of taxol, baccatin III and 10‐deacetylbaccatin III might transfer from the cytoplasm to the plastids, whereas the translocation of IPP might be not involved in cephalomannine biosynthesis. Furthermore, in combination with the results of previous studies, it is very probable that different IPP biosynthesis pathways exist during different growth phases in Taxus cells.
A new antibiotic, TH818, and its properties
Authors: Rachev R. , Gesheva V. , Tewfike T. , Bojkova S. , Zvetkova R.
Published: October 2003

Antibiotic TH818 was isolated and purified from a culture broth of Streptomyces fulvoviolaceus 818 by extraction and reversed‐phase liquid chromatography. The antibiotic TH818 possesses high molecular mass and unique structure, constructed from carbohydrates, amino acids and lipids. The hydrolysis experiments showed the presence of six fatty acids (hexadecanoic, hexadecenoic, octadecanoic, iso‐nonadecanoic, docosanoic and pentacosanoic acids), four sugars (glucose, galactose, N‐acetylglucosamine and N‐acetylgalactosamine), and seven amino acids (threonine, alanine, glutamic acid, glycine, serine and two unidentified). TH818 has a broad spectrum of anti‐microbial activity against Gram‐positive and Gram‐negative bacteria, yeasts and fungi.
Concentration and removal of prion proteins from biological solutions
Authors: Zeiler Brian , Adler Victor , Kryukov Valentin , Grossman Abraham
Published: October 2003

The pathogenesis of prion diseases is characterized by the accumulation of amyloid‐like rods or scrapie‐associated fibrils. The major protein component of scrapie‐associated fibrils is an abnormally folded isoform of the normal cellular prion protein (PrPC) that is resistant to digestion by proteinase K and is referred to as PrPSc. Purified human recombinant (hr PrP) was used to characterize the binding of a set of RNAs with affinity to PrP proteins. We report here that hr PrP has two RNA‐binding activities at physiological pH. One activity is capable of binding all of the screened RNAs with high affinity, whereas the other activity can bind only to a subset of the RNAs with high affinity in the presence of non‐specific competitor RNAs. A novel RNA belonging to the latter class, RQ11+12, bound to hr PrP with high affinity in the presence of vast molar excesses of competing RNAs. Beads impregnated with the RQ11+12 RNA were used to construct a filtration column. The column efficiently bound hr PrP and native PrPC from serum and urine. Importantly, the filtration device was also capable of binding proteinase K‐treated PrPSc from serum and urine. The level of sensitivity of detection of PrP by standard Western blotting was increased at least 1000‐fold by first concentrating PrP from solution with the filtration column.
Preparation of small unilamellar vesicles (SUV) and biophysical characterization of their complexes with poly‐l‐lysine‐condensed plasmid DNA
Authors: Maguire Leigh A. , Zhang Hu , Shamlou P. Ayazi
Published: October 2003

Liposomes have numerous applications in the (bio)pharmaceutical industries as agents in the synthesis of new biomaterials for use in areas including gene delivery. There is currently a need to establish efficient scaleable methods for the manufacture of liposomes, and in the present paper we describe the operation of a new high‐velocity jet homogenizer for downsizing of multilamellar large vesicles to produce small unilamellar vesicles (SUV). Measurements of size distribution of SUVs are presented and compared with mathematical simulations based on the solution of a population balance equation combined with computational‐fluid‐dynamics analysis of flow in the homogenizer. Anionic SUVs are produced by the new method and incubated with poly‐l‐lysine (PLL)‐condensed plasmid DNA (pDNA) to generate complexes under different physico‐chemical conditions. The colloidal properties of the resulting complexes, including their size and charge, are measured using a Zetasizer and the encapsulation efficiency is obtained experimentally using a Pico Green assay. The results show that between 85 and 95% of the PLL‐pDNA condensed plasmids were encapsulated by the liposomes, the smaller liposomes being more effective in encapsulating the complexes.
Public Service Professionalism for Performance Measurement and Evaluation
Authors: Caiden Naomi
Published: November 2003

For over fifty years, efforts have been made to measure the results of government activities. Most recently, performance measurement and evaluation have been key components of government reforms in many countries in reaction to loss of confidence in governments and budget stringency. Emphasis is on measuring outcomes or results within a general framework of strategic planning and objective setting, and in a context of devolution, managerial decentralization, and privatization. While it seems reasonable that governments should justify their use of public funds by demonstrating the effectiveness of their programs and activities, performance measurement in practice is by no means straightforward and demands considerable thought in its design and implementation.
Changing the Federal Tax Philosophy: A National Value‐Added Tax or Retail Sales Tax?
Authors: Mikesell John L.
Published: November 2003

Moving the federal government from its heavy reliance on taxes on income and profits to taxes on general consumption has been proposed as a way to improve equity, economic efficiency, and transparency of the tax system. The value‐added tax and the retail sales tax offer economically equivalent approaches to general consumption taxation, differing only in how they are administered. A comparison of the two taxes as they now operate, however, suggests considerable advantage for the value‐added tax as a national revenue source. Only in terms of requiring fewer businesses to collect the tax is there an advantage to the retail sales tax. The value‐added tax is superior or equivalent to the retail sales tax in other important fiscal criteria.
Umbrella Themes Obscure Real Problems: An Appraisal of Recent Efforts to Improve Financial Management
Authors: Premchand A.
Published: November 2003

Financial management in public bodies has been going through several changes either as a part of improvement of public management or because of specific attention to the process of stewardship of public money. As an integral part of these efforts, now known as new public management philosophy, several measures have been and are being taken by industrial and developing countries to develop general institutions as well as financial management machinery Meanwhile, the objectives sought to be served by financial management have grown substantially. This article formulates an analytical framework to assess the adequacy of the existing financial management systems and reaches the conclusion that the new public management philosophy can at best serve only a few of the specified objectives. The changing portfolio of public expenditures requires that more attention needs to be paid to the details and hitherto neglected high‐risk areas.
Investigations on Suitability of Different Materials for Carriers to be used for Virucidal testing of Chemical Disinfectants in the Veterinary Field
Authors: Yilmaz A. , Kaleta E. F.
Published: November 2003

Various materials with rough surfaces were tested to determine their suitability for virus carrier tests designed to evaluate virucidal activity of chemical disinfectants. A non‐enveloped RNA virus, bovine enterovirus type 1, strain LCR 4 [entero cytopathogenic bovine orphan virus (ECBO)] and an enveloped RNA virus, paramyxovirus type 1 [Newcastle disease virus (NDV), strain Montana] served as test viruses. Experiments with ECBO virus were carried out in four sets, and those with NDV in three sets. In the first set we used poplar wood, frosted glass slides and Sartorius membrane filters. The second set comprised of poplar wood, frosted glass slides, polyamide filters, and cellulose nitrate filters and, in the third set, glass fibre filters and glass fibre pre‐filters were added. The fourth test included poplar wood, frosted glass slides, and polyethersulphone ultra filters. Because of their extremely low levels of virus recovery, glass, polyamide, cellulose nitrate and glass fibre filter, glass fibre pre‐filter, and polyethersulphone ultra filters are not suitable for sufficient recovery of ECBO virus. Only poplar wood carriers allowed sufficient recovery rates of ECBO virus. In the first and second set of tests, NDV could be sufficiently recovered from poplar wood, glass slides, and polyamide filter. In the third set, the virus recovery from polyamide filter was very low. Poplar wood carrier is recommended as a reliable carrier for the tests with both viruses, but methods for virus recovery must be improved, e.g. by more vigorous and longer shaking or optimizing the ultrasonic treatment.
Visual impairment in childhood: insights from a community‐based survey
Authors: Flanagan N. M. , Jackson A. J. , Hill A. E.
Published: November 2003

Background  The concept of visual impairment (VI) in childhood has changed over the last 30 years. There has been a decrease in the number of children with an isolated visual problem and an increase in the numbers with VI and coexisting neurological disability. This study aimed to produce a profile of VI in childhood with a view to informing future services and to raise awareness of the need for comprehensive assessment including developmental remediation and educational advice.

Methods  Children with a VI were identified from multiple sources including hospital‐ and community‐based paediatricians and statutory blind registers.

Results  Seventy‐six children with a VI were identified giving a childhood prevalence of 1.61 per 1000. Thirty‐two per cent had a normal pattern of development. Global delays/severe learning difficulty were found in 43%. Only 21% of the children had an isolated VI. Additional medical problems were present in 79% of which cerebral palsy, occurring in 33%, was the most common. Nine per cent of the children were classified as totally blind. Cortical visual impairment was diagnosed in 45%. Twenty‐two per cent of the children were registered blind or partially sighted.

Conclusions  Most cases of VI in children did not appear on the statutory blind or partially sighted registers, thus these have limited value for service development. The implications for practice highlight the need for early assessment and advice from a co‐ordinated team to optimize visual potential in childhood.
An observational study investigating the health provision for children with epilepsy within secondary schools in the East Midlands, UK
Authors: Dunkley C. , Waldron B. , Ahmad N. , Whitehouse W.
Published: November 2003

Background  Epilepsy is a common medical condition affecting many children in mainstream education. The practice of local secondary schools and the health service with regard to pupils with epilepsy was examined. The extent to which these children had activities at schools restricted and the schools’ perception of the health service with regard to epilepsy was explored.

Method  A structured interview was conducted with selected staff members from mainstream secondary schools in East Midlands region, UK.

Results  Fourteen out of 17 schools participated. Fifty‐seven children were identified from a total pupil population of 14 534. Seven schools used the DOH/DfEE (The Department of Health/Department for Education and Employment) ‘Supporting Pupils with Medical Needs’ publication as a resource. No schools created individual health care plans for children with epilepsy. Six out of seven schools reported appropriate provision for children during swimming activities. The commonest restriction was related to computer use. Nine schools stated a need for more training for staff members with regard to seizure management.

Conclusions  Schools rely heavily on obtaining medical information from non‐medical sources. Individual health care plans for children with epilepsy are not commonly undertaken. Few children had any restriction or special provision placed upon them because of their epilepsy except in the area of computer use. Further action is needed to consider how the system for providing for such children can be improved so that each child's individual health needs can be satisfactorily met.
Defoliation tolerance affects the spatial and temporal distributions of larch sawfly and natural enemy populations
Authors: KRAUSE STEVEN C. , RAFFA KENNETH F.
Published: November 2003

Abstract.

The monophagous larch sawfly, Pristiphora erichsonii, requires larch, Larix spp., shoots for oviposition and foliage for larval development. The hypothesis that chronic defoliation reduces shoot availability for adult females, causing shifts in host use within plantations of L. decidua and L. leptolepis, was evaluated over a 3‐year period.

Larch productivity and sawfly abundance varied six‐ to 10‐fold among individual trees within each plantation. Sawflies concentrated oviposition on the most rapidly growing trees, and had a marginal impact on shoot production. Consequently, sawfly herbivory on individual trees remained relatively constant for 3 years, failing to support the hypothesis that P. erichsonii defoliation causes shifts in host use.

Pristiphora erichsonii larval performance varied 20–30% among individual host trees. The oviposition event did not significantly affect larval performance or foliar nutrient content.

The relationship between cocoon survival and natural enemy abundance was evaluated among fifteen L. leptolepis trees. Parasites and predators killed over 65% of the 18 315 cocoons sampled. The proportion of cocoons killed by parasitoids declined significantly with P. erichsonii density, while predation rates increased under heavily infested trees. Overall, the proportion of cocoons killed by parasitoids and predators did not vary with sawfly density.

Results indicate that components of host vigour, herbivore performance and natural enemy guilds exhibit substantial spatial heterogeneity among trees within plantations of exotic Larix trees. Moreover, individual larch can tolerate repeated oviposition and herbivory without a rapid loss in shoot production. The potential for host plant physiological tolerance to herbivory to interact with natural enemy population dynamics and behaviour so as to stabilize herbivore population patterns is discussed.
Hyperparasitoid aggregation in response to variation in Aphidius ervi host density at three spatial scales
Authors: SCHOOLER SHON S. , IVES ANTHONY R. , HARMON JASON
Published: November 2003

Abstract.

This article investigates the pattern of hyperparasitism of the host Aphidius ervi Haliday (Hymenoptera, Aphidiidae), a primary parasitoid of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae) at three spatial scales.

In the laboratory, the hyperparasitoid Asaphes lucens (Provancher) (Hymenoptera: Pteromalidae) was introduced into cages containing sixteen alfalfa plants with varying numbers of A. ervi mummies (the stage susceptible to hyperparasitism). The pattern of hyperparasitism at the end of the 48‐h trials showed no density‐dependent hyperparasitoid aggregation, although there was strong density‐independent hyperparasitoid aggregation.

In the field, the density of A. ervi mummies was manipulated in twelve 2 × 2‐m plots containing 1309–1654 alfalfa stems. Variation in hyperparasitism among plots showed no density‐dependent aggregation, although there was strong density‐independent aggregation.

Finally, at the largest scale of the study, the distribution of hyperparasitism was sampled among twelve alfalfa fields within a 5 × 3‐km area. At this scale there was both density‐dependent and density‐independent hyperparasitoid aggregation.

The natural variation in A. ervi mummy density is greatest at the larger scales of study. Therefore, density‐dependent hyperparasitism occurs only when there is high natural variation in mummy density.
A shift toward early reproduction in an introduced herbivorous ladybird
Authors: OHGUSHI TAKAYUKI , SAWADA HIROICHI
Published: November 2003

1. In May 1971, fifteen male and thirty female overwintering adults of a thistle‐feeding ladybird Epilachna niponica were taken from the Asiu Experimental Forest of Kyoto University and introduced into the Botanical Garden of Kyoto University, 30 km south of Asiu and 10 km south of the southern limits of its distribution. The introduced population established successfully and thereafter maintained densities sufficiently high to defoliate their host plants.

2. Reproductive parameters (reproductive lifespan of females, overall fecundity, and oviposition schedules) of the introduced population were compared with those of the source population 10 years after the introduction. Comparisons were made in the laboratory under five temperature regimes.

3. The lifespan of females differed significantly with temperature, decreasing linearly with increasing temperature. Temperature also had a significant effect on overall fecundity for both populations; overall fecundity at 15 and 30 °C was significantly lower than that at the 20–25 °C regimes.

4. The oviposition activity of the introduced population was significantly higher than that of the source population at 23 and 25 °C. The lifespan of females of the introduced population was also significantly shorter than those of the source population at 20 and 25 °C.

5. The reduced lifespan and higher oviposition activity of introduced females indicate that they directed greater reproductive efforts early in their reproductive lifetime than those of the source population.
On the role of body size for life‐history evolution
Authors: KLINGENBERG CHRISTIAN PETER , SPENCE JOHN
Published: November 2003

1. Body size is a central element in current theories of life‐history evolution. Models for optimal age at maturity are based on the assumptions that there is a trade‐off between development time and adult size and that larger size provides a reproductive advantage.

2. The results of large, replicated experiments with the water strider Gerris buenoi (Heteroptera: Gerridae) contradict both these assumptions. Individual rearings under field conditions showed that there is a negative, not a positive, correlation between development time and adult size. The physiological basis of growth, with stretch‐induced moulting, may provide a partial explanation for this correlation.

3. This study examined a number of fitness components for their correlations with female size: lifetime fecundity, reproductive life span, average volume per egg, total volume of eggs laid, and the proportion of eggs hatched. None of these traits was correlated with female size.

4. The data on water striders suggest an alternative scenario for life‐history evolution, in which size is not an adaptive trait, but evolves as a correlated response to selection on other traits. This expands the range of possible models, and opens life‐history theory to the debate about adaptation and optimality.
The effect of larval aggregation behaviour on larval growth of the spruce bark beetle Dendroctonus micans
Authors: STORER ANDREW , WAINHOUSE DAVID , SPEIGHT MARTIN
Published: November 2003

1. The great spruce bark beetle Dendroctonus micans is a primary pest of spruce in Europe. It is unusual among Eurasian scolytids in that apparently healthy trees are attacked by solitary adults, but larvae feed en masse, in response to a larval aggregation pheromone.

2. The effect of brood size on larval growth was determined in experiments on detached bark, logs and living trees. A positive relationship was found between brood size and larval growth in experiments started with either eggs or larvae up to fifth instar. The relationship appeared to be independent of the effects of both preformed and induced defences in bark.

3. No evidence was found to support the hypothesis that larvae feeding in groups spend a greater proportion of time feeding. Addition of resin to egg chambers in detached bark pieces resulted in high mortality of first‐instar larvae. A possible role for larval aggregation in minimizing the effects of host defences is discussed.
Mate‐locating strategies are related to relative body length and wing colour in the speckled wood butterfly Pararge aegeria
Authors: VAN DYCK HANS , MATTHYSEN ERIK , DHONDT ANDRE
Published: November 2003

1. The mate‐locating strategies of Pararge aegeria (L.) males were studied in relation to adult morphology (dorsal wing colour, forewing length, body length and forewing length : body length ratio) and generation.

2. Males locate females either by perching and defending territories, or by patrolling. Individuals were more consistent in their mating strategies than expected by chance.

3. Forewing length : body length ratio was positively correlated with thorax mass : body mass; relatively short‐bodied males had relatively heavy thoraxes. Therefore, forewing length : body length ratio was an index of mass allocation.

4. Perching males had higher forewing length : body length ratios and were paler than patrolling males.

5. The higher forewing length : body length ratio was due to the differences in body length and not wing length. Perchers had shorter bodies than patrollers.
Role of granivory and insectivory in the life cycle of the carabid beetle Amara similata
Authors: JØRGENSEN HELENE BRACHT , TOFT SØREN
Published: November 2003

1. The cereal field carabid beetle Amara similata was selected to elucidate the role of seeds and insects as food sources. Three experiments were performed to rank different weed seeds and insects in terms of food value: (i) fecundity in relation to adult diet, (ii) larval survival in relation to diet and (iii) larval survival in relation to parental diet.

2. Seeds were found to be of high value and insects of low value both for adults and larvae. Adding insects to a seed diet gave no significant improvement. The value of single species of seeds varied within adults and larvae, but also between adults and larvae. This is the first report that Amara larvae are granivorous.

3. The value of different insects varied by species. Cereal aphid species were of the lowest value both for adult and larval beetles. On a diet of mixed insects, the adults were able to produce a low number of eggs but the larvae all died before pupation.

4. There was no simple relation between survival of the larvae and the quality of the parents’ diet.
Causes of vertical stratification in the density of Cameraria hamadryadella
Authors: BROWN JESSI , VARGO STEVE , CONNOR EDWARD , NUCKOLS MICHAEL
Published: November 2003

1. The density of Cameraria hamadryadella, a leaf‐mining moth, is vertically stratified within the crown of oak trees. It occurs at higher densities on foliage in the lower crown.

2. Oviposition preference tests indicate that females display no preference to oviposit on foliage from the lower tree crown over foliage from the upper tree crown.

3. Experiments in which potted trees were placed at various heights indicate that foliage nearest ground level receives more oviposition, and that the higher rates of oviposition on foliage near the ground is not caused by differences in quality between foliage from low or high in the tree crown.

4. Host‐plant‐ and natural‐enemy‐mediated juvenile mortality and the abundance of parasitoids did not differ between the upper and lower crown.

5. Vertical differences in the timing of leaf production within the tree crown are unlikely to account for the observed gradient in the abundance of C. hamadryadella. Furthermore, the mean date of leaf fall does not differ among heights within the tree crown.

6. It is argued that microclimatic gradients and interspecific competition are also unlikely to account for the observed gradients in the density of C. hamadryadella within the tree crown.

7. Because of the absence of effects of other potentially causal factors, the most likely explanation for the gradient in density of C. hamadryadella is a lack of movement by females into the upper tree crown from overwintering, emergence, or resting sites located in the lower tree crown, combined with egg depletion by females as they move from the lower to the upper tree crown.

8. It is suggested that the lack of movement and egg depletion hypothesis should serve as the null hypothesis in studies of vertical stratification of tree‐feeding insects. In the absence of evidence of an effect of foliage quality, natural enemies, plant phenology, interspecific competition, or microclimate, the movement and egg depletion hypothesis is the most reasonable.
Detecting chaotic dynamics of insect populations from long‐term survey data
Authors: ZHOU X. , PERRY J. N. , WOIWOD I. P. , HARRINGTON R. , BALE J. S. , CLARK S. J.
Published: November 2003

1. Estimates of the Lyapunov exponent, a statistic that measures the sensitive dependence of the dynamic behaviour of a system on its initial conditions, are used to characterize several sets of insect time series.

2. A new method is described to overcome the difficulty of defining the dynamics of an observed, noisy, short ecological time series. This method provides two test statistics for the estimated Lyapunov exponent.

3. This method is applied to forty‐six time series comprising six aphid species from five sites and four moth species from six sites. There are few positive Lyapunov exponents and none is sufficiently large to characterize its time series as chaotic.

4. Two methods to estimate the Lyapunov exponent are compared; that based on logarithmically transformed counts yields less variable estimates for highly variable insect data than that based on untransformed counts.
Drought reduces breeding success of the butterfly Aglais urticae
Authors: POLLARD E. , GREATOREX‐DAVIES J.N. , THOMAS† J.A.
Published: November 2003

1. Published laboratory work suggests that Aglais urticae may be affected adversely by drought, as the larvae thrive on actively growing plants with high leaf water and nitrogen.

2. The weekly counts from the Butterfly Monitoring Scheme were used to test the hypothesis of an association between changes in abundance and drought in field data.

3. The analysis supported the hypothesis; breeding success of the summer generation from 1976 to 1995 was greater when the early summer weather was cool and wet than when it was warm and dry.
Abiotic and biotic factors influencing nest‐site selection by Halictus rubicundus, a ground‐nesting halictine bee
Authors: POTTS SIMON , WILLMER PAT
Published: November 2003

1. The nest‐site selection behaviour of the bee Halictus rubicundus (Christ) was examined both within and across sites in the U.K. Females utilized a range of edaphic and microclimatic conditions when choosing a site to excavate a nest. Factors with broad tolerances included slope and hardness; those with much narrower limits included aspect, soil humidity and soil particle composition.

2. There was a preference for softer soils that were easier to dig within a site with a low overall density, but in much denser aggregations problems of maintaining the structural integrity of a nest led to the utilization of harder soils.

3. The thermal advantages of having a warm nest meant that the most suitable areas were those with a southern aspect and a slope that maximized the absorption of solar radiation.

4. Limited areas of substrate with the most desirable characteristics resulted in gregarious nesting (‘limited substrate hypothesis’).

5. Natal nest‐site fidelity complemented the ‘limited substrate’ hypothesis in producing an aggregation of nests.
The influence of ants and water availability on oviposition behaviour and survivorship of a facultatively ant‐tended herbivore
Authors: WAGNER DIANE , KURINA LIANNE
Published: November 2003

1. The lycaenid butterfly Hemiargus isola associates facultatively with the ant species Formica perpilosa in arid areas of south‐western North America. Ants solicit liquid food rewards from butterfly larvae as larvae feed on the host plant, Acacia constricta. Previous studies have shown that tending by F. perpilosa enhances larval growth and pupal survivorship.

2. The effects of ants and plant water content on oviposition behaviour and survivorship to the last larval instar were tested by excluding ants and supplementing water to host plants in a two‐way factorial experiment.

3. Butterflies, which lay eggs singly on host plant inflorescences, laid significantly higher egg numbers and densities (eggs/inflorescence) on plants with ants than on plants without ants. This is the first report of a facultative, generalized ant‐associate using ants as oviposition cues. Water supplements increased the number, but not the density, of eggs laid on plants. Therefore, it appears that egg‐laying butterflies responded to number of inflorescences, rather than plant tissue water per se.

4. Plants with ants had significantly greater numbers of inflorescences during the experiment than plants without ants. Water supplements increased number of inflorescences slightly, but not significantly.

5. Ants increased larval survivorship. Twice as many fourth‐instar larvae survived per egg laid on plants with ants than on plants without ants. Ants did not reduce the number of predators present on acacias, but may have reduced predator effectiveness. Ants also did not reduce the numbers of potential H. isola competitors present.

6. Water supplementation affected neither the survivorship of H. isola larvae, nor the intensity of ant tending. Water supplementation did not affect the abundance of predators on plants, but did increase the abundance of several herbivorous insect taxa.