bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic diversity of green algal and cyanobacterial photobionts in Nephroma (Peltigerales)
Authors: Lohtander Katileena , Oksanen Ilona , Rikkinen Jouko 
Published: October 2003

AbstractGenetic diversity of green algal and cyanobacterial photobionts in Nephroma was examined by using nucleotide sequences of the ribosomal gene cluster. The lichens studied included both bipartite and tripartite species. There was very little variation in green algal-ITS sequences of N. arcticum and N. expallidum. Almost identical sequences were obtained from all thalli analysed and also from two tripartite Peltigera species. On the basis of SSU rDNA data the green algal photobionts of N. arcticum are closely related to the primary photobiont of P. britannica, and also to an endophytic alga of Ginkgo biloba. The SSU rDNA region of lichen-forming cyanobacteria was rather variable. A phylogenetic analysis indicated that the Nostoc specimens formed a monophyletic group and the strains were divided into two main groups. One clade included only cyanobionts of lichens, including those of all bipartite Nephroma species. The second group was genetically more heterogeneous and included mainly cyanobionts of terricolous cyanolichens, including those of both tripartite Nephroma species studied. The distinction between bi- and tripartite Nephroma species is significant as the mycobionts of tripartite species are not monophyletic. It implies that within Nephroma, evolutionary transitions between symbiosis types cannot have been achieved simply via an acquisition or loss of the green algal photobiont. As the Nostoc symbionts of bi- and tripartite species belong to different phylogenetic groups, an evolutionary change in green algal association has required a concurrent change in cyanobiont composition.
Spatial distribution of otter trawl effort in Icelandic waters: comparison of measures of effort and implications for benthic community effects of trawling activities
Authors: Ragnarsson Stefán Áki , Steingrímsson Sigmar Arnar 
Published: October 2003

AbstractWe examined the spatial distribution of trawling effort from logbook data from all Icelandic vessels fishing for demersal fish between 1991 and 1997 with a spatial resolution of 1 degree of latitude and 1 degree of longitude. The trawling effort was widely distributed but was intensive only in small and localised areas. Three measures of effort were compared; tow frequency, tow duration and separate estimates of swept area for otter boards and trawls. In each year, the area swept with otter trawl was 1.7 times greater than the total area in which fishing occurred over the 7 year period. In contrast, the area swept with otter boards was 4% of the total fishing area. Most of the fishing effort was confined to depths shallower than 400 m. With increasing depth, the size of trawls became larger and accordingly, also the area swept per haul. Calculations assuming no variation in the size of the trawl in relation to depth, produced inaccurate swept area estimates. Furthermore, swept area estimates based on depth corrected door spreads were greater than estimates where no such correction was made. Swept area was considered to be a more appropriate measure of effort than tow frequency and tow duration as long as variation in the size of the gear (e.g. in relation to depth) was taken into account. Effort within Icelandic waters was compared in five depth strata within seven zones. Effort was highest off the south and NW coasts and lowest off the north and east coasts. Effort was most intensive at the 100–500 m depth in all zones but in some areas (such as off NW Iceland), effort extended to deeper waters. Knowledge of the distribution of fishing effort is important for predicting larger scale effects of fishing gears on benthic communities.
The role of incisors in selective grazing by cattle and horses
Authors: HONGO A. , AKIMOTO M. 
Published: October 2003

To clarify the role of the incisors in selective grazing by cattle and horses, experiments were conducted in July 1999, using three Holstein cattle and three thoroughbred horses to investigate bite weight and bite force using hand-constructed swards with 15 loadcells spaced 6×12 cm apart. Leaves of perennial ryegrass (Lolium perenne: PRG) were mixed with leaves of tall fescue (Festuca arundinacea: TF) or reproductive culms of reed canarygrass (Phalaris arundinacea: RCG).There was little difference between cattle and horses in bite rate, but DM intake rate of horses was almost twice that of cattle in the PRG/TF mixture. In the PRG/RCG mixture, both animals tended to graze only leaves of PRG. Total bite force was 3270–3280 N/min in cattle and 5350–6350 N/min in horses in the PRG/TF mixture. Means of maximum values of one bite force (not total force per bite) were 88±5·5 N in cattle and 141±11·0 N in horses. These values corresponded to 1·6±0·10% of body weight in cattle and 2·2±0·16% in horses, after converting Newton force into kilogram force. Bite area was higher in horses than in cattle. Both cattle and horses did not discriminate between leaves of PRG and TF. In the PRG/RCG mixture, horses prehended both leaves and culms in 33% of total clumps grazed, compared with only 5% in cattle. Many culms escaped from the mouth at the moment of prehension. In mixtures of soft leaves and stiff stems, the lack of upper incisors in cattle may have the advantage over horses. The term ‘comb-out strategy’ is proposed for this selective foraging by cattle. DM intake per bite force was highest in TF leaves (7·5 mg DM/N) grazed by horses and similar (3·7–4·6 mg DM/N) in PRG leaves grazed by both cattle and horses.
The effect of organic and inorganic fertilizers on soil physical condition and the productivity of a rice–lentil cropping sequence in India
Authors: SARKAR S. , SINGH S. R. , SINGH R. P. 
Published: October 2003

A field experiment lasting 9 years was initiated in 1987 to study the effect of integrated nutrient management involving incorporation of wheat straw (WS) or farmyard manure (FYM) alone or in combination with inorganic fertilizer on a fine loamy mixed hyperthermic udic Ustochrept. Soil physical properties and the productivity of a rice–lentil cropping sequence were examined in a dry land farming system.At the end of the ninth cropping season, addition of organic materials had increased organic carbon, aggregate stability, moisture retention capacity and infiltration rate of the surface soil while reducing the bulk density. Application of inorganic fertilizer alone decreased the stability of macro aggregates and moisture retention capacity but increased the bulk density values. Treatment effects on moisture retentivity were more pronounced in the higher (0·3–1·5 MPa) suction range. During the first six experimental years, sole application of inorganic fertilizers produced 10–17% higher grain yield of rice, compared to sole application of organic sources or combined organic and inorganic sources. Annual applications of wheat straw and farmyard manure gave higher grain yields of rice from the seventh year onwards. Grain yields of lentil were higher with organic sources either alone or combined with inorganic nutrients.
Social Capital: Policy and Politics
Authors: Franklin Jane 
Published: October 2003

S. Baron, J. Field and T. Schuller (eds) (2000) Social Capital: Critical Perspectives, Oxford University Press, OxfordA. Portes (1998) ‘Social capital: its origins and perspectives in modern sociology’, Annual Review of Sociology, 243, 1, 1–24.R. Putnam (2000) Bowling Alone: The Collapse and Revival of American Community, Simon & Schuster, New York
Metamorphic synchrony and aggregation as antipredator responses in American toads
Authors: DeVito Jill 
Published: October 2003

Safety in numbers serves as an antipredator defense strategy in many organisms, as aggregation can reduce the probability of predation for individual group members. It has long been suggested that some organisms are under selective pressure to synchronize vulnerable life stages with conspecifics, but there have been very few experimental tests of this hypothesis. Furthermore, the role of aggregation of conspecific animals within cohorts during vulnerable life stages is poorly understood.Previous studies indicate that predation pressure may select for synchronous metamorphosis and the subsequent formation of metamorphic aggregations in North American toad species. In a series of laboratory experiments, I demonstrated that 1) Bufo americanus tadpoles in the presence of a predator exhibit higher levels of aggregation than tadpoles maintained in the absence of predator stimuli, and 2) B. americanus exposed to predator chemical cues metamorphose more synchronously than control tadpoles. I also found that toads at the climax of metamorphosis exhibit higher levels of aggregation than pre‐metamorphic individuals. These results support the hypothesis that predation pressure has played a role in selection for life stage synchrony, and that aggregation serves as an antipredator defense in animals with synchronous transitions.
Designer blood vessels and therapeutic revascularization
Authors: Berglund Joseph D , Galis Zorina S 
Published: October 2003

Inadequate vascular perfusion leads to fatal heart attacks, chronic ulcers, and other serious clinical conditions. The body's capacity to restore vascular perfusion through angiogenesis and arteriogenesis is often impaired by pre‐existing disease, and availability of native replacements for nonfunctional arteries is limited in many patients. Thus, recreating blood vessels of various calibres through novel engineering technologies has emerged as a radical option among therapeutic strategies for revascularization. Ranging from artificial, recycled or reassembled natural conduits to sophisticated microdevices, we refer to these as ‘designer blood vessels’. Our common efforts to continuously improve vascular replacement design have provided many clues about our own blood vessels, but nature's ability to create nonthrombogenic, immunocompatible, strong, yet biologically responsive blood vessels remains unparalleled. Just as art reproductions never equal the original masterpiece, designer blood vessels may never attain nature's perfection. Nevertheless, they will provide a valuable option as long as they come close enough and are available to many.British Journal of Pharmacology (2003) 140, 627–636. doi:10.1038/sj.bjp.0705457
Paracrine control of vascularization and neurogenesis by neurotrophins
Authors: Emanueli Costanza , Schratzberger Peter , Kirchmair Rudolf , Madeddu Paolo 
Published: October 2003

The neuronal system plays a fundamental role in the maturation of primitive embryonic vascular network by providing a paracrine template for blood vessel branching and arterial differentiation. Furthermore, postnatal vascular and neural regeneration cooperate in the healing of damaged tissue.
Neurogenesis continues in adulthood although confined to specific brain regions. Following ischaemic insult, neural staminal cells contribute towards the healing process through the stimulation of neurogenesis and vasculogenesis.
Evidence indicates that nerves and blood vessels exert a reciprocal control of their own growth by paracrine mechanisms. For instance, guidance factors, including vascular endothelial growth factor A (VEGF‐A) and semaphorins, which share the ability of binding neuropilin receptors, play a pivotal role in the tridimensional growth pattern of arterial vessels and nerves.
Animal models and clinical studies have demonstrated a role of VEGF‐A in the pathogenesis of ischaemic and diabetic neuropathies. Further, supplementation with VEGF‐A ameliorates neuronal recovery by exerting protective effects on nerves and stimulating reparative neovascularization. Human tissue kallikrein, a recently discovered angiogenic and arteriogenic factor, accelerates neuronal recovery by stimulating the growth of vasa nervorum.
Conversely, the neurotrophin nerve growth factor, known to regulate neuronal survival and differentiation, is now regarded as a stimulator of angiogenesis and arteriogenesis.
These results indicate that angiogenesis and neurogenesis are paracrinally regulated by growth factors released by endothelial cells and neurons. Supplementation of these growth factors, alone or in combination, could benefit the treatment of ischaemic diseases and neuropathies.

British Journal of Pharmacology (2003) 140, 614–619. doi:10.1038/sj.bjp.0705458
Submucosal microinfusion of endothelin and adrenaline mobilizes ECL‐cell histamine in rat stomach, and causes mucosal damage: a microdialysis study
Authors: Bernsand M , Ericsson P , Björkqvist M , Zhao C ‐M , Håkanson R , Norlén P 
Published: October 2003

Rat stomach ECL cells release histamine in response to gastrin. Submucosal microinfusion of endothelin or adrenaline, known to cause vasoconstriction and gastric lesions, mobilized striking amounts of histamine. While the histamine response to gastrin is sustainable for hours, that to endothelin and adrenaline was characteristically short‐lasting (1–2 h).
The aims of this study were to identify the cellular source of histamine mobilized by endothelin and adrenaline, and examine the differences between the histamine‐mobilizing effects of gastrin, and of endothelin and adrenaline.
Endothelin, adrenaline or gastrin were administered by submucosal microinfusion. Gastric histamine mobilization was monitored by microdialysis.
Local pretreatment with the H1‐receptor antagonist mepyramine and the H2‐receptor antagonist ranitidine did not prevent endothelin‐ or adrenaline‐induced mucosal damage. Submucosal microinfusion of histamine did not cause damage. Acid blockade by ranitidine or omeprazole prevented the damage, suggesting that acid back diffusion contributes.
Gastrin raised histidine decarboxylase (HDC) activity close to the probe, without affecting the histamine concentration. Endothelin and adrenaline lowered histamine by 50–70%, without activating HDC. Histamine mobilization declined upon repeated administration. Endothelin reduced the number of histamine‐immunoreactive ECL cells locally, and reduced the number of secretory vesicles. Thus, unlike gastrin, endothelin (and adrenaline) is capable of exhausting ECL‐cell histamine.
Microinfusion of α‐fluoromethylhistidine (known to deplete ECL cells but not mast cells of histamine) reduced the histamine‐mobilizing effect of endothelin by 80%, while 1‐week pretreatment with omeprazole enhanced it, supporting the involvement of ECL cells.
Somatostatin or the prostanoid misoprostol inhibited gastrin‐, but not endothelin‐stimulated histamine release, suggesting that endothelin and gastrin mobilize histamine via different mechanisms.
While gastrin effectively mobilized histamine from ECL cells in primary culture, endothelin had no effect, and adrenaline, a modest effect. Hence, the striking effects of endothelin and adrenaline on ECL cells in situ are probably indirect, possibly a consequence of ischemia.

British Journal of Pharmacology (2003) 140, 707–717. doi:10.1038/sj.bjp.0705473
Roles of KATP channels in delayed cardioprotection and intracellular Ca2+ in the rat heart as revealed by κ‐opioid receptor stimulation with U50,488H
Authors: Chen Mai , Zhou Jing‐Jun , Kam Kenneth Wan‐Lung , Qi Jian‐Song , Yan Wing‐Yi , Wu Song , Wong Tak‐Ming 
Published: October 2003

The effect of preconditioning with U50,488 H (UP), a selective kappa‐opioid receptor (κ‐OR) agonist, on infarct size and intracellular Ca2+ ([Ca2+]i) in the heart subjected to ischaemic insults were studied and evaluated. U50,488 H administered intravenously reduced the infarct size 18–48 h after administration in isolated hearts subjected to regional ischaemia/reperfusion (I/R). The effect was dose dependent. A peak effect was reached at 10 mg kg−1 U50,488 H and at 24 h after administration. The effect of 10 mg kg−1 U50,488 H at 24 h after administration was abolished by nor‐binaltorphimine (nor‐BNI), a selective κ‐OR antagonist, indicating the effect was κ‐OR mediated.
The infarct reducing effect of U50,488 H was attenuated when a selective blocker of mitochondrial (5‐hydroxydecanoic acid, 5‐HD) or sarcolemmal (HRM‐1098) ATP‐sensitive potassium channel (KATP) was coadministered with U50,488 H 24 h before ischaemia or when 5‐HD was administered just before ischaemia.
U50,488 H also attenuated the elevation in [Ca2+]i and reduction in electrically induced [Ca2+]i transient in cardiomyocytes subjected to ischaemic insults. The effects were reversed by blockade of KATP channel, which abolished the protective effect of preconditioning with U50,488 H.
The results indicated that mitochondrial KATP channel serves as both a trigger and a mediator, while sarcolemmal KATP channel as a trigger only, of delayed cardioprotection of κ‐OR stimulation. The effects of these channels may result from prevention/attenuation of [Ca2+]i overload induced by ischaemic insults.

British Journal of Pharmacology (2003) 140, 750–758. doi:10.1038/sj.bjp.0705475
Chronic oral supplementation with sepiapterin prevents endothelial dysfunction and oxidative stress in small mesenteric arteries from diabetic (db/db) mice
Authors: Pannirselvam Malarvannan , Simon Valerie , Verma Subodh , Anderson Todd , Triggle Chris R 
Published: October 2003

We previously reported that acute incubation with tetrahydrobiopterin (BH4) or sepiapterin, a cofactor for endothelial nitric oxide synthase and a stable precursor of BH4, respectively, enhanced the acetylcholine (Ach)‐induced relaxation of isolated small mesenteric arteries (SMA) from diabetic (db/db) mice. In this study, we investigated the effect of chronic oral supplementation of sepiapterin (10 mg kg−1 day−1) to db/db mice on endothelium function, biopterin levels and lipid peroxidation in SMA.
Oral dietary supplementation with sepiapterin had no effect on glucose, triglyceride, cholesterol levels and body weight. SMA from db/db mice showed enhanced vascular reactivity to phenylephrine, which was corrected with sepiapterin supplementation. Furthermore, Ach, but not sodium nitroprusside‐induced relaxation, was improved with sepiapterin supplementation in db/db mice.
BH4 levels and guanosine triphosphate cyclohydrolase I activity in SMA were similar in db/+ and db/db mice. Sepiapterin treatment had no effects on BH4 or guanosine triphosphate cyclohydrolase I activity. However, the level of dihydrobiopterin+biopterin was higher in SMA from db/db mice, which was corrected following sepiapterin treatment.
Thiobarbituric acid reactive substance, malondialdehyde, a marker of lipid peroxidation, was higher in SMA from db/db mice, and was normalized by sepiapterin treatment.
These results indicate that sepiapterin improves endothelial dysfunction in SMA from db/db mice by reducing oxidative stress. Furthermore, these results suggest that decreased biosynthesis of BH4 may not be the basis for endothelial dysfunction in SMA from db/db mice.

British Journal of Pharmacology (2003) 140, 701–706. doi:10.1038/sj.bjp.0705476
Regulation of leptin distribution between plasma and cerebrospinal fluid by cholecystokinin receptors
Authors: Cano Victoria , Ezquerra Laura , Ramos M Pilar , Ruiz‐Gayo Mariano 
Published: October 2003

Cholecystokinin (CCK) is a postprandial hormone that elicits a satiating effect and regulates feeding behaviour. CCK has been shown to enhance the effect of leptin in several experimental paradigms.
The goal of this work was to characterize the effect of endogenous CCK on plasma leptin content by using CCK receptor antagonists. Therefore, we administered SR‐27,897, a selective CCK1 receptor antagonist, and L‐365,260, a selective CCK2 receptor antagonist, to fed and food‐deprived rats and determined plasma leptin concentration by enzyme immunoassay. Plasma insulin and glucose concentration as well as food intake were also determined.
Under our conditions, SR‐27,897 increased plasma concentration of leptin both in fed and food‐deprived rats. It also increased food intake as well as plasma concentration of insulin in fed animals. L‐365,260 increased plasma leptin concentration only in fed rats.
In animals receiving exogenous leptin, CCK‐8 increased the ratio between the concentration of leptin in cerebrospinal fluid and plasma.
These results show that CCK receptor antagonists increases plasma concentration of leptin and suggest that endogenous CCK may facilitate the uptake of plasma leptin to the cerebrospinal fluid.

British Journal of Pharmacology (2003) 140, 647–652. doi:10.1038/sj.bjp.0705477
Expression of Rho‐kinase and its functional role in the contractile activity of the mouse vas deferens
Authors: Büyükafşar Kansu , Levent Adnan , Ark Mustafa 
Published: October 2003

The effects of two Rho‐kinase inhibitors, Y‐27632 and fasudil, were investigated on the contractions produced by electrical field stimulation (EFS, 40 V, 1 mS, 2, 4, 8 and 16 Hz, for 20 s), KCl (30 – 60 mM), phenylephrine (Phe) (10−5 – 10−4 M), adenosine‐3′, 5′‐triphosphate (ATP) (10−4 – 10−3 M) and α,β‐methylene ATP (10−5 M).
EFS produced frequency‐dependent reproducible contractile activity, which was almost abolished by guanethidine (10−5 M, for 1 h). This contraction consisted of two components (a phasic initial contraction followed by a tonic one), and it was inhibited by Y‐27632 and fasudil (both at 10−5 M). However, these inhibitors had no effect on resting tension of the tissue.
Contractions elicited by KCl (30 – 60 mM) were insensitive to guanethidine (10−5 M, for 1 h), but suppressed by Y‐27632 (10−5 M) and fasudil (10−5 M). In addition, the contractions induced by Phe (an α1‐adrenoceptor agonist) and ATP (a purinergic agent) were inhibited significantly by Y‐27632 (10−5 M). Phasic contractions evoked by the selective P2X purinoceptor agonist α,β‐methylene ATP were also suppressed by Y‐27632 (10−5 M).
Western blot analysis revealed that the mouse vas deferens expresses Rho‐kinase (ROKα, ROCK‐2 isoform) protein with a molecular weight of approximately 160 kDa. As a positive control, the presence of this protein was also shown in homogenates of smooth muscle from the rat mesenteric artery.
In conclusion, Rho‐kinase protein is expressed in the mouse vas deferens, and it mediates neurogenic contractile activity as well as the contractions induced by KCl, Phe, ATP and α,β‐methylene ATP. Owing to the suppressive effects of Rho‐kinase inhibitors on the contractile activity of the vas deferens, the possibility that these compounds might impair ejaculation must be taken into account when considering them as potential agents in the treatment of erectile dysfunction.

British Journal of Pharmacology (2003) 140, 743–749. doi:10.1038/sj.bjp.0705479