bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial distribution of bluetongue virus and its Culicoides vectors in Sicily
Authors: Torina A. , Caracappa S. , Mellor P. S. , Baylis M. , Purse B. V.
Published: June 2004

Abstract.  During the recent Mediterranean epizootic of bluetongue, an extensive programme of serological and vector (Culicoides biting midges (Diptera: Ceratopogonidae)) surveillance was carried out across Sicily. This paper presents the analysis of 911 light trap catches collected at the times of peak Culicoides abundance (summer to autumn 2000–2002) in 269 sites, in order to produce detailed maps of the spatial distribution of the main European vector, Culicoides imicola Kieffer and that of potential novel vectors. Whereas C. imicola was found at only 12% of sites, potential novel vectors, Culicoides obsoletus group Meigen, Culicoides pulicaris Linnaeus and Culicoides newsteadi Austen were present at over 50% of sites. However, the spatial distribution of C. imicola showed the closest correspondence to that of the 2000 and 2001 bluetongue (BT) outbreaks and its presence and abundance were significant predictors of the probability of an outbreak, suggesting that it was the main vector during these years. Although C. imicola may have played a role in transmission in several sites near Paternó, it was absent from the majority of sites at which outbreaks occurred in 2002 and from all sites in the province of Messina. All three potential novel vectors were widespread across sites at which outbreaks occurred during 2002. Of these, C. newsteadi was an unlikely candidate, as it was significantly less prevalent in outbreak vs. non‐outbreak sites in Messina. It is hypothesized that the yearly distribution and intensity of outbreaks is directly attributable to the distribution and abundance of the vectors involved in transmission during each year. When C. imicola operated as the main vector in 2000 and 2001, outbreaks were few in number and were restricted to coastal regions due to low abundance and prevalence of this species. In 2002, it is hypothesized that BTV transmission was handed over to more prevalent and abundant novel vector species, leading to numerous and widespread outbreaks and probably to overwintering of the virus between 2001 and 2002. Based on catch ranges in outbreak vs. non‐outbreak sites, it is tentatively suggested that nightly catches of 400 or more C. obsoletus and 150 or more C. pulicaris allow BTV transmission at a site, and provide a strategy for a fuller examination of the relationship between BTV transmission and the abundance and distribution of different vector species.
Infestation of people with lice in Kathmandu and Pokhara, Nepal
Authors: Poudel S. K. S. , Barker S. C.
Published: June 2004

Abstract.  The prevalence of infestation with head lice and body lice, Pediculus spp. (Phthiraptera: Pediculidae) and pubic (crab) lice Pthirus pubis (L.) (Phthiraptera: Pthiridae), was recorded from 484 people in Nepal. The prevalence of head lice varied from 16% in a sample of people aged 10–39 years of age, to 59% in street children. Simultaneous infestations with head and body lice (double infestations) varied from 18% in slum children to 59% in street children.
Temperature‐related duration of aquatic stages of the Afrotropical malaria vector mosquito Anopheles gambiae in the laboratory
Authors: Bayoh M. N. , Lindsay S. W.
Published: June 2004

Abstract.  Vector abundance is an important factor governing disease risk and is often employed when modelling disease transmission. The longevity of the aquatic stages of mosquitoes (Diptera: Culicidae) dictates the rate of production of adults and hence the intensity of disease transmission. We examined how temperature influences the survival of larval stages (larvae and pupae) of Anopheles gambiae Giles sensu stricto and subsequent adult production of this most efficient malaria vector. Groups of 30 mosquitoes were reared at constant temperatures (from 10 to 40 °C) from the first instar and observed until death or metamorphosis of the last individual. Larvae developed into adults at temperatures ranging from 16 to 34 °C. Larval survival was shortest (< 7 days) at 10–12 °C and 38–40 °C, and longest (> 30 days) at 14–20 °C. Within the temperature range at which adults were produced, larval mortality was highest at the upper range 30–32 °C, with death (rather than adult emergence) representing over 70% of the terminal events. The optimal survival temperatures were lower than the temperatures at which development was quickest, suggesting a critical relationship between temperature and the life cycle of the insect. These data provide fundamental information about An. gambiae s.s. adult productivity at different temperatures, which may facilitate the construction of process‐based models of malaria risk in Africa and the development of early warning systems for epidemics.
Locating Responsibility: The Sphere Humanitarian Charter and Its Rationale
Authors: Darcy James
Published: June 2004

Criticised by some as a technical initiative that neglects core principles, Sphere was seen by its originators precisely as an articulation of principle. The Humanitarian Charter was the main vehicle through which this was expressed, but its relationship to the Minimum Standards has remained a matter of uncertainty. Specifically, it was unclear in the original (1999) edition of Sphere how the concept of rights informed the Minimum Standards. The revised (2004) edition goes some way to clarifying this in the way the standards are framed, yet the link between the standards and the charter remains unclear.

The concern with the quality and accountability of humanitarian assistance, which motivated the attempt to establish system‐wide standards through the Sphere Project, was accompanied by a desire to establish such actions in a wider framework of legal and political responsibility. In part, this reflects the conditional nature of the undertaking that agencies make when they adopt Sphere. This aspect of the charter has been neglected, but it is fundamental to an understanding of the standards and their application.

This paper considers the rationale of the Sphere Humanitarian Charter and the conceptual model that underpins it. It discusses the relationship between the charter and the Minimum Standards, and the sense in which the latter are properly called ‘rights‐based’ (explored further in a related paper herein by Young and Taylor). The author was closely involved in the conception and drafting of the charter, and this paper attempts to convey some of the thinking that lay behind it.
Linking Rights and Standards: The Process of Developing ‘Rights‐based’ Minimum Standards on Food Security, Nutrition and Food Aid
Authors: Young Helen , Taylor Anna , Way Sally‐Anne , Leaning Jennifer
Published: June 2004

This article examines the recent revision of the Sphere Minimum Standards in disaster response relating to food security, nutrition and food aid. It describes how the revision attempted to incorporate the principles of the Humanitarian Charter, as well as relevant human rights principles and values into the Sphere Minimum Standards. The initial aim of the revision was to ensure that the Sphere Minimum Standards better reflected the principles embodied in the Humanitarian Charter. This was later broadened to ensure that key legal standards and principles from human rights and humanitarian law were considered and also incorporated, in part to fill the ‘protection gap’ within the existing standards. In relation to the food security, nutrition and food aid standards, it was agreed by participants in the process that the human right to adequate food and freedom from hunger should be incorporated. In relation to more general principles underlying the Humanitarian Charter, itself drawn largely from human rights and humanitarian law, it was agreed that there was a need to strengthen ‘protection’ elements within the standards and a need to incorporate the basic principles of the right to life with dignity, non‐discrimination, impartiality and participation, as well as to explore the relevance of the concept of the progressive realisation of the right to food.

The questions raised in linking rights to operational standards required thought, on the one hand, about whether the technical standards reflected a deep understanding of the values expressed within the legal instruments, and whether the existing standards were adequate in relation to those legal rights. On the other hand, it also required reflection on how operational standards like Sphere could give concrete content to human rights, such as the right to food and the right to be free from hunger. However, there remain challenges in examining what a rights‐based approach will mean in terms of the role of humanitarian agencies as duty‐bearers of rights, given that the primary responsibility rests with state governments. It will also require reflection on the modes and mechanisms of accountability that are brought to bear in ensuring the implementation of the Minimum Standards.
The United Nations' Humanitarian Pillar: Refocusing the UN's Disaster and Emergency Roles and Responsibilities
Authors: Kent Randolph C.
Published: June 2004

Changes in the nature of humanitarian crises and in the ways that the international community responds to such crises demand a radically overhauled role for the United Nations system. At a time when the UN and its member states are pursuing reform of some of that institution's most fundamental peace and security functions, this paper suggests that reform, too, is required to meet humanitarian crises of the future. This paper proposes a new type of operational role for the UN, while at the same time arguing that the UN has to place itself in the vanguard of humanitarian assistance as ‘the standard‐bearer’.

The article draws many of its conclusions and recommendations from a recently completed study, requested by the Inter‐Agency Standing Committee, concerning the effect for the UN system of changes in humanitarian financing.
Regional expression of RGS4 mRNA in human brain†
Authors: Erdely Holly A. , Lahti Robert A. , Lopez Mary B. , Myers Carol S. , Roberts Rosalinda C. , Tamminga Carol A. , Vogel Michael W.
Published: June 2004

Regulators of G‐protein signalling (RGS) proteins are a recently discovered class of proteins that modulate G‐protein activity. More than 20 RGS proteins have been identified and are expressed throughout the body and brain. In particular, RGS4 appears to regulate dopamine receptor function and has been implicated in several dopamine related diseases, including schizophrenia. This study presents an extensive examination of the regional distribution of RGS4 mRNA in postmortem human brain. Using in situ hybridization, the expression levels of RGS4 mRNA were determined in human hemicoronal (Talairach sections +8 and −20) brain sections. In the rostral slice (Talairach +8) highest levels were found in the inferior frontal cortex, the superior frontal, and the cingulate cortex. Slightly lower levels were found in the insular cortex and inferior temporal cortex. The caudate, putamen and nucleus accumbens had lower levels. In the caudal slice (−20), the cortical layers showed the highest levels, with moderate levels observed in the parahippocampal gyrus, low levels in the CA‐pyramidal region, and almost undetectable levels in the thalamus. In the frontal cortex a dense band was apparent near one of the inner layers of the cortex. In conclusion, RGS4 mRNA distribution in human postmortem tissue from normal persons was very dense in most cortical layers examined, with lower density in the basal ganglia and thalamus.
Development of the mouse hypothalamo‐neurohypophysial system in the munc18–1 null mutant that lacks regulated secretion
Authors: Korteweg Niki , Maia Ascanio S. , Verhage Matthijs , Burbach J. Peter H.
Published: June 2004

The hypothalamo‐neurohypophysial system (HNS) is composed of hypothalamic magnocellular neurons and neural lobe pituicytes that accommodate the nerve terminals. Here we have investigated if the communication of the peptidergic neurons of the HNS with neighbouring cells plays a role in the development and assembly of the HNS. We employed munc18–1‐deficient mice, which completely lack neurotransmitter secretion. Morphological and immunohistological analysis of the HNS in these mutant embryos during brain development showed that this peptidergic system was formed normally during early embryogenesis. However, the development arrested at embryonal day 14.5, the stage when terminal differentiation has to take place. The peptidergic neurons targeted axons in the correct direction, but few arrived at their final location and the neurons were not maintained in later stages. The pituicytes in the neural lobe of the pituitary were generated, but failed to organize normally. Our results indicate that peptide gene expression, axon outgrowth and migration are intrinsic developmental events in these peptidergic neurons, that are initiated in the munc18–1 null mutant. The further expansion and the integration of outgrowing axon terminals with neural lobe pituicytes requires munc18–1‐dependent processes, probably exocytosis, at multiple levels. Firstly, to maintain and propagate neuronal outgrowth and guidance, and secondly, to control the cellular organization of the pituicytes. Thus, the communication between the outgrowing neurons and the pituicytes could serve to integrate these two cell types to constitute a functional peptidergic system.
The therapeutic window after spinal cord injury can accommodate T cell‐based vaccination and methylprednisolone in rats
Authors: Ibarra Antonio , Hauben Ehud , Butovsky Oleg , Schwartz Michal
Published: June 2004

Immune system activity has traditionally been considered harmful for recovery after spinal cord injury (SCI). Recent evidence suggests, however, that immune activity – and specifically autoimmune activity − is evoked by the insult, is beneficial if properly regulated and is amenable to boosting. Thus, for example, vaccination with an altered peptide ligand derived from myelin basic protein reduces the progressive degeneration of neurons that escaped the initial insult, thereby promoting recovery after SCI. As the steroid drug methylprednisolone (MP) is currently the only treatment available for patients with SCI, our purpose in the present study was to examine the mutual compatibility of the two treatments within the post‐traumatic therapeutic window. We show, using rats of two different strains, that if MP is injected concomitantly with the therapeutic vaccination, the beneficial effect of the vaccination is diminished. However, if MP is given immediately after the insult and the vaccination 48 h later, MP does not detract from the beneficial effect of the vaccination. These results demonstrate that the therapeutic window after SCI can accommodate immediate administration of MP plus a delayed therapeutic vaccination.
Irreversible loss of a subpopulation of cortical interneurons in the absence of glutamatergic network activity
Authors: De Lima Ana Dolabela , Opitz Thoralf , Voigt Thomas
Published: June 2004

In the cerebral cortex of mammals, γ‐aminobutyric acid (GABA)ergic neurons represent 15–25% of all neurons, depending on the species and area being examined. Because converging evidence suggests that activity may play an important role in the neuritic maturation and synaptic function of GABAergic neurons, it is feasible that activity plays a role in the regulation of the proportion of GABAergic neurons. Here we provide direct evidence that early in cortical development activity blockade may deplete the network of a subpopulation of GABA immunoreactive neurons characterized by their small size and late generation in vitro. In a period of time coinciding with the emergence of synchronous network activity, the survival and morphological differentiation of GABAergic neurons was influenced by long‐term blockade of synaptic activity. While GABAA receptor antagonists had a minor promoting effect on interneuronal survival during the second week in vitro, antagonists of ionotropic glutamate receptors strongly impaired survival and differentiation of immature GABAergic interneurons. Interneuronal loss was more severe when N‐methyl‐d‐aspartate receptors were blocked than after blockade of α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐proprionic acid (AMPA)/kainate receptors. The decrease in the density of GABAergic neurons was irreversible, but could be prevented by the simultaneous addition of brain‐derived neurotrophic factor (BDNF). These results suggest that there is a narrow time window during neocortical development when glutamatergic activity, and specially NMDA receptor stimulation, is crucial to assure survival and maturation of a subpopulation of late developing GABAergic interneurons.
Phasic bursts in rat magnocellular neurosecretory cells are not intrinsically regenerative in vivo
Authors: Brown Colin H. , Bull Philip M. , Bourque Charles W.
Published: June 2004

Vasopressinergic hypothalamic magnocellular neurosecretory cells fire in phasic bursts. Burst initiation involves summation of postsynaptic potentials to generate action potentials. Action potentials are each followed by a nonsynaptic depolarizing after‐potential that summates temporally to generate a plateau potential and so sustain activity throughout the burst. It is unknown whether this plateau potential exceeds spike threshold in vivo to cause intrinsic regenerative firing or simply approaches threshold to increase the probability that excitatory postsynaptic potentials will trigger further action potentials. Here we show that pharmacological blockade of ionotropic glutamatergic transmission by microdialysis application of kynurenic acid into the supraoptic nucleus of anaesthetized rats prevents spontaneous bursts and bursts (after‐discharge) evoked by short trains of antidromically stimulated action potentials in magnocellular neurosecretory cells. Even during prolonged depolarization induced by 1 m NaCl infusion, kynurenic acid microdialysis application still blocked after‐discharge. The ability of kynurenic acid to block after‐discharge during osmotic stimulation was not caused by an unmasking of inhibitory postsynaptic potentials as kynurenic acid was equally effective in the presence of the ionotropic γ‐aminobutyric acid receptor antagonist, bicuculline, nor did it result from inhibition of plateau potential amplitude as this was unaffected by kynurenic acid and bicuculline in vitro, as was after‐discharge evoked in vitro. We conclude that phasic bursts are nonregenerative in vivo but rather require continued excitatory synaptic input activity superimposed upon a subthreshold plateau potential to sustain burst activity.
Absence of phosphoglucose isomerase‐1 in retinal photoreceptor, pigment epithelium and Muller cells
Authors: Archer Simon N. , Ahuja Poonam , Caffé Romeo , Mikol Catherine , Foster Russell G. , Van Veen Theo , Von Schantz Malcolm
Published: June 2004

Macroarray analysis was used to compare equal amounts of cDNA from wild‐type and rd/rd (retinal degeneration) mice, collected at P90 when photoreceptor degeneration is virtually complete. A stronger signal for the glycolytic enzyme phosphoglucose isomerase (Gpi1) was observed in the rd/rd sample. Extracellularly, Gpi1 may act as a cytokine, independently described as neuroleukin and autocrine motility factor. Retinal Gpi1 expression was investigated by Northern and Western blot analysis and immunohistochemistry. Double‐labelling was performed with antibodies against Gpi1 and calbindin‐D, glutamine synthetase, RPE65, calretinin and ultraviolet opsin in order to provide positive cell type identification. Northern and Western blots showed double expression levels per microgram of RNA and protein, respectively, in the rd/rd retina compared with wild‐type. However, the total amount of Gpi1 protein per retina was indistinguishable. Gpi1 immunoreactivity was found in ganglion, amacrine, horizontal and bipolar cells, but not in rods, cones, pigment epithelium and Muller cells. This distribution explains why the absolute amounts of Gpi1 protein were not appreciably different between wild‐type and the rd/rd phenotype, where rods and cones are absent, whilst the relative contribution of Gpi1 to the total protein and RNA pools differed. Some extracellular immunoreactivity was observed in the photoreceptor matrix around cones in freshly fixed tissue only, which could possibly reflect a role as a cytokine. We propose that glycolysis in Gpi1‐negative cells proceeds entirely through the pentose phosphate pathway, creating NADPH at the cost of organic carbon. We hypothesize that the unique metabolic needs of photoreceptors justify this trade‐off.
Postnatal emergence of mature release properties in terminals of rat fast‐ and slow‐twitch muscles
Authors: Bewick Guy S. , Reid Brian , Jawaid Sabiha , Hatcher Tina , Shanley Lynne
Published: June 2004

Motor nerve terminals in adult mammalian slow‐twitch muscles have lower levels of spontaneous and evoked neurotransmitter release than terminals in fast‐twitch muscles. These reflect adaptive differences, allowing terminals in slow (postural) muscles to sustain release during the prolonged firing trains experienced in vivo. Here we ask whether these differences in terminal release properties in Sprague–Dawley rat extensor digitorum longus (EDL, fast) and soleus (slow) muscles reflect their early cytodifferentiation in the embryo or whether they might be adaptations to their distinct mature activity patterns, which emerge around two weeks postnatally. We find that the mature pattern of differences in release arise through co‐ordinated increases in presynaptically dependent release properties (quantal content, spontaneous release frequency and evoked potential amplitude), beginning at three weeks, which are particularly substantial in EDL. In contrast, other synaptic properties are either consistently greater in the same muscle throughout development (evoked potential kinetics, muscle fibre diameter) or display no systematic muscle type‐dependent differences (terminal area, input resistance, spontaneous release amplitude). Thus, the emergence of adaptive differences in terminal release properties correlates with the differentiation of locomotor activity patterns in postnatal rat hindlimb muscles.
Glutamate‐induced elevations in intracellular chloride concentration in hippocampal cell cultures derived from EYFP‐expressing mice
Authors: Slemmer Jennifer E. , Matsushita Shinichi , De Zeeuw Chris I. , Weber John T. , Knöpfel Thomas
Published: June 2004

The homeostasis of intracellular Cl− concentration ([Cl−]i) is critical for neuronal function, including γ‐aminobutyric acid (GABA)ergic synaptic transmission. Here, we investigated activity‐dependent changes in [Cl−]i using a transgenetically expressed Cl−‐sensitive enhanced yellow‐fluorescent protein (EYFP) in cultures of mouse hippocampal neurons. Application of glutamate (100 µm for 3 min) in a bath perfusion to cell cultures of various days in vitro (DIV) revealed a decrease in EYFP fluorescence. The EYFP signal increased in amplitude with increasing DIV, reaching a maximal response after 7 DIV. Glutamate application resulted in a slight neuronal acidification. Although EYFP fluorescence is sensitive to pH, EYFP signals were virtually abolished in Cl−‐free solution, demonstrating that the EYFP signal represented an increase in [Cl−]i. Similar to glutamate, a rise in [Cl−]i was also induced by specific ionotropic glutamate receptor agonists and by increasing extracellular [K+], indicating that an increase in driving force for Cl− suffices to increase [Cl−]i. To elucidate the membrane mechanisms mediating the Cl− influx, a series of blockers of ion channels and transporters were tested. The glutamate‐induced increase in [Cl−]i was resistant to furosemide, bumetanide and 4,4′‐diisothiocyanato‐stilbene‐2,2′‐disulphonic acid (DIDS), was reduced by bicuculline to about 80% of control responses, and was antagonized by niflumic acid (NFA) and 5‐nitro‐2‐(3‐phenylpropylamino)benzoic acid (NPPB). We conclude that membrane depolarization increases [Cl−]i via several pathways involving NFA‐ and NPPB‐sensitive anion channels and GABAA receptors, but not through furosemide‐, bumetanide‐ or DIDS‐sensitive Cl− transporters. The present study highlights the vulnerability of [Cl−]i homeostasis after membrane depolarization in neurons.
Behavioral training interferes with the ability of gonadal hormones to increase CA1 spine synapse density in ovariectomized female rats
Authors: Frick Karyn M. , Fernandez Stephanie M. , Bennett Jennifer C. , Prange‐Kiel Janine , MacLusky Neil J. , Leranth Csaba
Published: June 2004

Estradiol benzoate (EB) has repeatedly been shown to increase hippocampal CA1 spine synapse density in ovariectomized female rats. Although this increase has been assumed to enhance memory, a direct link between increased spine synapse density and memory has not been demonstrated. Furthermore, while androgens, such as testosterone propionate (TP) and dihydrotestosterone (DHT), also increase spine synapse density in females, their effects on memory have yet to be investigated. In the present study, ovariectomized female rats were given two injections, 24 h apart, of sesame oil (control), 10 µg EB, 500 µg TP or 500 µg DHT. Forty‐eight hours after the second injection, rats were tested in a 1‐day spatial Morris water maze task and then immediately perfused for analysis of CA1 spine synapse density (using electron microscopy and unbiased stereology). In the spatial acquisition phase of testing, EB, but not TP or DHT, significantly impaired memory relative to controls. Hormone treatment did not affect spatial retention or performance in the non‐spatial phase of testing. In contrast to previous work, spine synapse density was not increased by EB, TP or DHT. We therefore examined a new set of EB‐treated females, only half of which were water maze tested. Consistent with previous work, EB significantly increased spine synapse density among behaviorally naïve females. In contrast, spine synapse densities did not differ among behaviorally tested control and EB females, although they were higher than behaviorally naïve controls. These data indicate that 1‐day water maze testing can eliminate the hormone‐induced increases in CA1 spine synapse density typically observed in behaviorally naïve females.
Endocannabinoid transport tightly controls 2‐arachidonoyl glycerol actions in the hippocampus: effects of low temperature and the transport inhibitor AM404
Authors: Hájos Norbert , Kathuria Satish , Dinh Thien , Piomelli Daniele , Freund Tamás F.
Published: June 2004

The control of endocannabinoid actions on cortical neurons by a putative carrier‐mediated uptake is still poorly understood at the level of synaptic transmission. We investigated the effect of an endocannabinoid, 2‐arachidonoyl glycerol (2‐AG), on inhibitory postsynaptic currents (IPSCs) in hippocampal slices under physiological conditions, and when uptake was altered by a selective blocker or lower temperature. Bath application of 2‐AG (20 µm) caused a 40% reduction in the amplitude of IPSCs evoked in the perisomatic region of CA1 pyramidal neurons at room temperature; this effect could be blocked by a specific CB1 receptor antagonist, AM251. By contrast, a smaller (20%) but significant suppression of inhibitory transmission was found by 2‐AG at 33–35 °C. This reduced blocking effect at physiological temperature could be brought back to 40% by coapplying the endocannabinoid uptake blocker, AM404 (10 or 20 µm) with 2‐AG. In parallel experiments, we measured [3H]2‐AG uptake at different temperatures in primary cultures prepared from cortical neurons. These data confirmed a striking inhibition of [3H]2‐AG uptake at room temperature compared with values observed at 37 °C. Uptake could be significantly modified by anandamide, 2‐AG and AM404, suggesting a common transporter for the two endocannabinoids. These findings together demonstrate the presence of an effective endocannabinoid uptake in cortical neurons, which could considerably alter the spatial and temporal constraints of endocannabinoid signalling at physiological temperature, and which may critically change the interpretation of findings at room temperature.
DREAM ablation selectively alters THC place aversion and analgesia but leaves intact the motivational and analgesic effects of morphine
Authors: Cheng Hai‐Ying M. , Laviolette Steven R. , Van Der Kooy Derek , Penninger Josef M.
Published: June 2004

DREAM (downstream regulatory element antagonistic modulator) is a novel transcriptional repressor for the prodynorphin gene, and genetic deletion of DREAM in mice results in a phenotype of ongoing analgesia by virtue of its effect on opioid gene expression. In the present study, we evaluated the motivational effects of opioids (morphine), cannabinoids [Δ9‐tetrahydrocannabinol (THC)] and cocaine in mice lacking the dream gene (dream−/−). The aversive effects of THC were potentiated in dream−/− mice in a κ‐opioid receptor‐dependent fashion, whereas morphine reward and the aversive effects of morphine withdrawal remained intact. The rewarding and aversive effects of cocaine were likewise unperturbed in dream−/− mice. Moreover, the aversive properties of lithium chloride and naloxone were unaffected by the absence of DREAM, indicating that the effect of DREAM on THC‐induced dysphoria is not due to a general involvement in the behavioral response to aversive stimuli. Additionally, physical dependence to morphine and the locomotor‐sensitizing effects of cocaine were unaltered in these animals. Finally, whereas the absence of DREAM reduced the analgesic efficacy of THC, morphine analgesia was unaffected in dream−/− mice.
Muscle dysfunction during exercise of a single skeletal muscle in rats with congestive heart failure is not associated with reduced muscle blood supply
Authors: Schiøtz Thorud H.‐M. , Lunde P. K. , Nicolaysen G. , Nicolaysen A. , Helge J. W. , Nilsson G. E. , Sejersted O. M.
Published: June 2004

Aim:  Inadequate muscle blood flow is a possible explanation for reduced fatigue resistance in patients with congestive heart failure (CHF).

Methods:  In rats with post‐infarction CHF we electrically stimulated the soleus muscle (SOL) in situ with intact blood supply. Contractile properties, blood flow, high‐energy phosphates and metabolites were measured during 30 min of intermittent stimulation, and in addition capillarization of SOL was recorded.

Results:  During stimulation, SOL contracted more slowly in rats with CHF compared with sham‐operated rats. However, the blood flow in SOL was unaltered and capillary density was maintained in CHF rats. Further, the content of ATP, ADP, AMP, NAD, CrP, Pi and lactate in SOL was not different between the groups.

Conclusion:  The cause of contractile dysfunction in a single exercising skeletal muscle in rats with CHF cannot be explained simply by reduced blood supply. In addition, absence of changes in high‐energy phosphates and metabolites indicate that the oxidative metabolism of SOL is intact in rats with CHF.
Effects of oxytocin in normal man during low and high sodium diets
Authors: Rasmussen M. S. , Simonsen J. A. , Sandgaard N. C. F. , Høilund‐Carlsen P. F. , Bie P.
Published: June 2004

Aim:  We tested the hypothesis that oxytocin in normal man causes natriuresis by means of nitric oxide and/or atrial natriuretic peptide.

Methods:  Normal male subjects were investigated after 4 days of sodium controlled diets (30 mmol sodium chloride day−1, n = 8 or 230 mmol sodium chloride day−1, n = 6). Oxytocin was infused intravenously (1 pmol kg−1 min−1 for 240 min).

Results:  Mean arterial blood pressure, heart rate and glomerular filtration rate by clearance of chromium‐labelled ethylenediaminetetraacetate remained stable. Plasma oxytocin increased from 2 to 3 pg mL−1 to around 50 pg mL−1. Oxytocin decreased urine flow (4.2 ± 0.2–0.75 ± 0.11 and 4.6 ± 1.3–1.4 ± 0.6 mL min−1, low‐ and high‐salt diet, respectively). During low‐salt conditions, oxytocin reduced sodium and potassium excretion (11 ± 2–4 ± 2 and 93 ± 19–42 ± 3 μmol min−1, respectively). Plasma renin, angiotensin II, aldosterone and renal excretion of metabolites of nitric oxide (nitrate and nitrite) all decreased. Plasma atrial natriuretic peptide and cyclic guanosine monophosphate were unchanged. A similar pattern was obtained during high‐salt conditions but in this case the antinatriuresis was not different from that occurring during the corresponding time control series.

Conclusions:  The data reject the hypothesis. In contrast, we found significant antinatriuretic, antikaliuretic and antidiuretic effects, which were not mediated by the renin–angiotensin–aldosterone system, atrial natriuretic peptide, systemic haemodynamics, or processes increasing urinary excretion of metabolites of nitric oxide. The natriuretic effect of oxytocin found in laboratory animals is species‐specific.
Breeding for resistance to begomovirus in tropic‐adapted tomato genotypes
Authors: Góamez O. , Piñón M. , Martínez Y. , Quiñónes M. , Fonseca D. , Laterrot H.
Published: June 2004

Four tomato lines introgressed from Lycopersicon chilense were compared with the commercial F1 hybrids ‘ARO 8479’ and ‘HA 3108’, which are tolerant to Tomato yellow leaf curl virus, and the cv. ‘Campbell 28’ as a susceptible control. Resistance was evaluated by the use of grafted diseased scions as well as in a field trial where plants infected by viruliferous whiteflies and disease‐free plants were transplanted in paired rows. The new lines LD 3, LD 4, LD 5 and LD 6 showed no disease symptoms after grafting or in the field trial. Virus accumulation at 60 days after transplanting was low in the infected plants: 0.09, 0.60, 1.00 and 0.50 ng, respectively. No fruit‐set or yield losses were registered under the high temperature conditions prevalent in the trial, in which lines LD 5 and LD 6 were better adapted to tropical conditions. Viral DNA concentrations were over 1000 ng in the cvs.‘Campbell 28′,‘ARO 8479’ and ‘HA 3108’. The last two are considered tolerant as they were asymptomatic or had mild symptoms, respectively, but achieved acceptable yields in the trial. By contrast, virus had a negative effect on fruit‐set, number of fruit per plant and total yield in the cv.‘Campbell 28’.
A genetic linkage map of rhodesgrass based on an F1 pseudo‐testcross population
Authors: Ubi B. E. , Fujimori M. , Mano Y. , Komatsu T.
Published: June 2004

The linkage relationships between 164 polymorphic amplified fragment length polymorphism (AFLP) and 25 restriction fragment length polymorphism (RFLP) fragments assayed in a pseudo‐testcross population generated from the mating of single genotypes from two divergent cultivars were used to construct female, ‘Katambora’ (‘Kat’) and male, ‘Tochirakukei’ (‘Toch’) parental genetic maps for rhodesgrass. The ‘Kat’ genetic map consists of 84 marker loci (72 AFLP and 12 RFLP markers) distributed on 14 linkage groups and spans a total length of 488.3 cM, with an average distance of 7.8 cM between adjacent markers. The ‘Toch’ genetic map consists of 61 marker loci (52 AFLP and nine RFLP) mapped on 12 linkage groups spanning a total length of 443.3 cM, with an average spacing of 9.0 cM between adjacent markers. About 23% of the markers remained unassigned. The level of segregation distortion observed in this cross was 11.1%. In both maps, linked duplicated RFLP loci were found. These linkage maps will serve as a starting point for linkage studies in rhodesgrass with potential application for marker‐assisted selection in breeding programmes.
Identification of a major blast resistance gene in the rice cultivar ‘Tetep’
Authors: Barman S. R. , Gowda M. , Venu R. C. , Chattoo B. B.
Published: June 2004

Analysis of near‐isogenic lines (NILs) indicated the presence of a novel resistance gene in the indica rice cultivar ‘Tetep’ which was highly resistant to the rice blast fungus Magnaporthe grisea.‘Tetep’ was crossed to the widely used susceptible cultivar ‘CO39’ to generate the mapping population. A Mendelian segregation ratio of 3 : 1 for resistant to susceptible F2 plants further confirmed the presence of a major dominant locus, in ‘Tetep’, conferring resistance to the blast fungal isolate B157, corresponding to the international race IC9. Simple sequence length polymorphism (SSLP) was used for molecular genetic analysis. The analysis revealed that the SSLP marker RM 246 was linked to a novel blast resistance gene designated Pi‐tp(t) in ‘Tetep’.
Genetic diversity in Cynara cardunculus revealed by AFLP markers: comparison between cultivars and wild types from Sicily*
Authors: Raccuia S. A. , Mainolfi A. , Mandolino G. , Melilli M. G.
Published: June 2004

Genetic diversity in 49 plants of 16 accessions representing one wild and two cultivated taxa of Cynara cardunculus L. (wild cardoon, cultivated cardoon and globe artichoke) was investigated using amplified fragment length polymorphic (AFLP) analysis. Four pairs of primers identified a total of 264 scorable loci, 196 of which were polymorphic. The number of markers scored per primer combination ranged from 41 to 107, with an average of 66 markers per primer combination. All the primer combinations detected polymorphism. The data were used for cluster analysis and AMOVA. The clusters obtained are in agreement with the current botanical classification and the differences among the taxa were substantial. The eco‐geographical groups within wild cardoon are clearly separated in relative subclusters, and reflect the geography of the collection areas. The six clones of the four cultivated artichoke varieties were clearly separated into four subclusters, corresponding to the current classification which is based on morphological traits. The results obtained may have a direct and important bearing on plant genetic resource conservation and management and on breeding.
Genetic analysis of resistance to root‐lesion nematode (Pratylenchus thornei) in wheat
Authors: Zwart R. S. , Thompson J. P. , Godwin I. D.
Published: June 2004

The inheritance of resistance to root‐lesion nematode was investigated in five synthetic hexaploid wheat lines and two bread wheat lines using a half‐diallel design of F1 and F2 crosses. The combining ability of resistance genes in the synthetic hexaploid wheat lines was compared with the performance of the bread wheat line ‘GS50a’, the source of resistance to Pratylenchus thornei used in Australian wheat breeding programmes. Replicated glasshouse trials identified P. thornei resistance as polygenic and additive in gene action. General combining ability (GCA) of the parents was more important than specific combining ability (SCA) effects in the inheritance of P. thornei resistance in both F1 and F2 populations. The synthetic hexaploid wheat line ‘CPI133872’ was identified as the best general combiner, however, all five synthetic hexaploid wheat lines possessed better GCA than ‘GS50a’ The synthetic hexaploid wheat lines contain novel sources of P. thornei resistance that will provide alternative and more effective sources of resistance to be utilized in wheat breeding programmes.
Heterosis performance of yield and fibre quality in F1 and F2 hybrids in upland cotton
Authors: Wu Y. T. , Yin J. M. , Guo W. Z. , Zhu X. F. , Zhang T. Z.
Published: June 2004

Because of the difficulty of producing F1 hybrid seeds by hand emasculation and pollination, wide use of heterosis in cotton production has been limited in China. The objective of this study was to evaluate the potential of F2 hybrids for yield and fibre quality. A half diallel involving eight parents and their F1 and F2 hybrids was grown in replicated studies at Linqing and Nanjing in 1999 and Nanjing in 2000. Yield and fibre quality was determined for all 64 entries. Fibre quality was also determined for parents and F1s, but only for Zhongmiansuo 28 (ZMS28), Xiangzamian 2 (XZM2) and Wanmian 13 (WM13) F2s. These three F2 hybrids are extensively planted in China and provide experimental controls with which to compare the performance of new hybrids. Average yield heterosis for F1s and F2s was 15.9 and 9.2%, respectively. Inbreeding depression for yield varied but some F2s greatly out‐yielded the best variety. Average F1 heterosis was 6.7, 6.2 and 2.9%, respectively for number of bolls per unit area, boll weight, and lint percentage. The average F2 heterosis for the same traits was 4.4, 3.3 and 1.6%, respectively. F1 heterosis for fibre traits was low. In general, parental average was a good indicator of the yield and fibre quality of F1 hybrids. These encouraging results suggest there is sufficient heterosis for yield to use F2s in China.
Phenotypic and genotypic variation in seed production traits within a full‐sib family of meadow fescue
Authors: Fang C. , Aamlid T. S. , Jørgensen Ø. , Rognli O. A.
Published: June 2004

Phenotypic and genotypic variation for seed yield and associated traits (heading date, plant height, number of fertile tillers, 1000‐seed weight, panicle length, seed weight per panicle, fertility, flag‐leaf length and flag‐leaf width) were studied in a full‐sib family of meadow fescue using replicated clonal trials at two locations in Norway. Genotypic variances were highly significant for all traits and genotype × location interactions were significant for heading date, number of fertile tillers and seed yield. Seed yield and other seed component traits exhibited the largest genotypic variations. Heading date showed large genotype × location interaction, probably because of the very diverse origin of the two parents of the full‐sib family. Path coefficient analysis showed that panicle fertility, measured as seed weight per unit length of panicles, was by far the most important component trait contributing to seed yield, followed by the number of fertile tillers, plant height and flag‐leaf width. Flag‐leaf width and plant height had sizeable indirect effects on seed yield via panicle fertility. This is the first time that the importance of the size of the flag leaf for seed yield in herbage grasses has been demonstrated.
Radiomutants of chrysanthemum (Dendranthema grandiflora Tzvelev) of the Lady group: RAPD analysis of the genetic diversity
Authors: Lema‐Rumiñska J. , Zalewska M. , Sadoch Z.
Published: June 2004

Random amplified polymorphic DNA (RAPD) markers were used to study the molecular characterization of 10 new radiomutants of chrysanthemum. The original cultivar ‘Richmond’ differed in genetic distance from its Lady group mutants. The analysis of genetic similarity indices revealed low diversity within the radiomutants. The dendrogram obtained after cluster analysis separated the new cultivars as a group that differed from the original cultivar ‘Richmond’. The Lady group cultivars, derived from one original cultivar by radiomutation, could be distinguished from each other by using RAPD markers of only a single primer or sets of two or three primers. Polymerase chain reaction analysis proved the efficiency of the RAPD method for DNA fingerprinting of the original cultivar ‘Richmond’ and its new radiomutants.
Morphological and AFLP variation of Porphyra yezoensis Ueda form, narawaensis Miura (Bangiales, Rhodophyta)
Authors: Niwa Kyosuke , Kikuchi Norio , Iwabuchi Mitsunobu , Aruga Yusho
Published: June 2004

Detailed morphological observations were made on two strains of cultivated Porphyra: HG‐1 (pure line isolated from Dai‐1) and Noriken‐4 (parental strain of a pure line HG‐4). The two strains were identified as P. yezoensis f. narawaensis based on their macroscopic and microscopic features, such as long linear or oblanceolate blades up to 50 cm in maximum length, division formulae of spermatangia and zygotosporangia, shape of trichogynes and carpogonia, and the second transverse divisional plane formed at the division from c/2 to c/4 in zygotosporangia. Gametophytic blades from two completely homozygous conchocelis strains isolated in this study (HG‐1 and HG‐4) were cultured under the same conditions and compared to confirm whether the differences in their shapes are genetically determined. The shape of blades from both of conchospores and monospores was always more slender in HG‐4 than in HG‐1 at the same blade age, suggesting that the difference in the blade shape between the two pure lines is due to genetic variation. To estimate the level of genetic variation the two pure lines were subjected to amplified fragment length polymorphism fingerprint analysis. A total of 230 bands were detected in HG‐1 and HG‐4 using eight selective primer pairs, and the number of polymorphic bands was only two in HG‐1. These results indicate that the two pure lines certainly show genetic variation, which is, however, at an extremely low level. The importance of pure‐line breeding and the origin of currently cultivated Porphyra are discussed. This is the first report to identify currently cultivated Porphyra strains in Japan based on combined results of detailed morphological observations and molecular analysis.
Russian Railways Reform and the Problem of Non‐discriminatory Access to Infrastructure
Authors: Pittman Russell
Published: June 2004

Abstract Restructuring of the Russian railways system is well under way. Among the policies just now coming into practice are two that are standard in railways restructuring in other countries: the provision of access to the infrastructure by independent train operating companies, and assurances of non‐discriminatory access terms for such companies. However, ‘discrimination’– in the traditional economic sense – is a standard and often welfare‐enhancing pricing strategy for the recovery of fixed costs in a sector, like railways, with declining average costs. If competition regulators are unable to distinguish between discrimination that harms competition and discrimination designed only to recover fixed costs, policy makers in Russia and elsewhere will face a choice between large government subsidies and large welfare losses. In these circumstances, other restructuring models should be considered.
Regulating Public Transit Networks: How do Urban‐Intercity Diversification and Speed‐up Measures Affect Firms’ Cost Performance?
Authors: Fraquelli Giovanni , Piacenza Massimiliano , Abrate Graziano
Published: June 2004

Abstract Empirical studies on the cost structure of Public Transit Networks are mainly based on specialized firms providing urban or intercity services. In this study we estimate a translogarithmic variable cost function to assess the behaviour of returns to scale and the impact of network characteristics. The analysis is based on a sample of 45 Italian municipal companies observed from 1996 to 1998 and including both specialized and mixed transit operators. Results confirm previous evidence on the existence of natural monopoly in the industry and support a regulation introducing competitive tenders to access to the market. In addition, we provide insights about the advantages associated with urban‐intercity diversification and with the improvement of network commercial speed. Cost benefits can then be achieved by promoting mergers between neighbouring firms, so as to create new companies operating on integrated local networks and supplying in combination urban and intercity public transport. Implications of such a strategy for the design of tender mechanisms are also underlined, together with the need for a regulatory policy which takes more care of speed‐up measures.
La Création D’activité: Prise D’autonomie Et Médiation Entre Acteurs
Authors: Ferraton Cyrille , Vallat David
Published: June 2004

Résumé Depuis le début des années 1980 des initiatives d’accompagnement et de financement de petites activités économiques à destination des personnes en situation d’exclusion économique et sociale se sont développées dans les pays du Nord. Relevant du champ du « tiers secteur », et en particulier de l’économie solidaire contemporaine, elles visent à la fois à répondre à des besoins insatisfaits et à introduire le principe d’un droit à l’initiative économique. Leur conception des inégalités économique et sociale, axée sur l’approche par les capabilités d’Amartya Sen, permet de comprendre leur mode d’organisation combinant une double dimension financière et sociale.