bluuebunny/crossref_metadata_2025 huggingface dataset:
Common allometric equations for estimating the tree weight of mangroves
Authors: Komiyama Akira , Poungparn Sasitorn , Kato Shogo
Published: June 2005

Inventory data on tree weights of 104 individual trees representing 10 mangrove species were collected from mangrove forests in South-East Asia to establish common allometric equations for the trunk, leaf, above-ground and root weight. We used the measurable tree dimensions, such as dbh (trunk diameter at breast height), DR0.3 (trunk diameter at 30 cm above the highest prop root of Rhizophora species), DB (trunk diameter at lowest living branch), and H (tree height) for the independent variable of equations. Among the mangrove species studied, the trunk shape was statistically identical regardless of site and species. However, ρ (wood density of tree trunk) differed significantly among the species. A common allometric equation for trunk weight was derived, when dbh2H or DR0.32H was selected as the independent variable and wood density was taken into account. The common allometric equations for the leaf and the above-ground weight were also derived according to Shinozaki's pipe model and its extended theory. The common allometric relationships for these weights were attained with given ρ of each species, when DB2 or dbh2 or DR0.32 was selected as the independent variable. For the root weight, the common equation was derived from the allometric relationship between root weight and above-ground weight, since these two partial weights significantly correlated with each other. Based on these physical and biological parameters, we have proposed four common allometric equations for estimating the mangrove tree weight of trunk, leaf, above-ground part and root.
Placeboeffekt und Bedeutung
Authors: Schneider Rainer
Published: June 2005

Zusammenfassung. Der Placeboeffekt (PE) beinhaltet bedeutsame Heilmechanismen, wenn Placebos nicht alleine als Kontrollsubstanz verwendet werden. Diese sind mit Effekten tatsächlicher Interventionen vergleichbar. Viele Fragen zu den Mechanismen sind allerdings ungelöst. Dies liegt zu einem Teil in der Reduzierung psychologischer Mechanismen auf bewusste Denkinhalte. Es wird ein funktional orientierter Ansatz vorgestellt, die Persönlichkeits-System-Interaktionen-Theorie (PSI-Theorie), die psychische Funktionen und deren Dynamik beschreibt. Ihm zufolge ist der PE an ein spezifisches System gebunden, das Extensionsgedächtnis (EG) genannt wird. Es besteht aus weitgehend impliziten Netzwerken, integriert (Selbst-)Aspekte und ist eng an somatosensorische Systeme gekoppelt. Eine Reihe von (neuro-)psychologischen Befunden steht mit dieser Auffassung in Einklang. Die vorgestellten Forschungsideen erlauben ein besseres Verständnis für psychologische Mechanismen, die im therapeutischen Kontext eine Rolle spielen, aber auch für die pharmakologische Testpraxis Konsequenzen haben.
Topiramate inhibits trigeminovascular activation: an intravital microscopy study
Authors: Akerman Simon , Goadsby Peter J
Published: June 2005

Activation, or the altered perception of activation, of trigeminal nerves that innervate the cranial vasculature is considered to be a pivotal component of the pathophysiology of acute migraine.

Calcitonin gene‐related peptide (CGRP) levels are increased during migraine and after trigeminal nerve stimulation in the cat. Both CGRP and nitric oxide (NO) infusion causes headache and delayed migraine in migraineurs. Neurogenic stimulation of a cranial window, CGRP and NO injection all cause meningeal artery dilation in the rat when viewed using intravital microscopy.

Topiramate is an antiepileptic drug with established efficacy as a migraine preventive, and has recently been shown to inhibit neurons of the trigeminocervical complex after superior sagittal sinus stimulation.

In this study, we used intravital microscopy with neurogenic dural vasodilation, and CGRP‐ and NO‐induced dilation to examine whether intravenous topiramate has effects on the trigeminovascular system.

Topiramate was able to attentuate neurogenic dural vasodilation maximally after 15 min by 52% at 30 mg kg−1 (t5=6.78, n=6); there was no significant inhibition at 10 mg kg−1.

There was also significant attenuation of the NO‐induced dilation maximally after 15 min, at both 10 and 30 mg kg−1 by 21% (t6=6.09, n=7) and 41% (t6=5.3, n=7), respectively.

CGRP‐induced dilation was not inhibited at either dose of topiramate.

The study demonstrates that topiramate is likely to inhibit neurogenic dural vasodilation by inhibiting the release of CGRP from prejunctional trigeminal neurons, thus attenuating the dural vasodilation. Topiramate is not able to act postsynaptically at the blood vessels themselves as the CGRP‐induced dilation was not attenuated.

The data are consistent with an effect of topiramate on trigeminovascular activation which may form part of its preventive antimigraine mechanisms of action.

British Journal of Pharmacology (2005) 146, 7–14. doi:10.1038/sj.bjp.0706290
Effects of (2R)‐(3‐amino‐2‐fluoropropyl)sulphinic acid (AFPSiA) on transient lower oesophageal sphincter relaxation in dogs and mechanism of hypothermic effects in mice
Authors: Lehmann Anders , Holmberg Ann Aurell , Bhatt Ulhas , Bremner‐Danielsen Marianne , Brändén Lena , Elg Susanne , Elebring Thomas , Fitzpatrick Kevin , Geiss William B , Guzzo Peter , Jensen Jorgen , Jerndal Gunilla , Mattsson Jan P , Nilsson Karolina , Olsson Britt‐Marie
Published: June 2005

The effects of the novel GABA analogue (2R)‐(3‐amino‐2‐fluoropropyl)sulphinic acid (AFPSiA) on transient lower oesophageal sphincter relaxations (TLOSRs) were studied in the dog. In addition, the GABAA/GABAB selectivity was determined in vitro and in vivo, and the pharmacokinetics and the metabolism of the compound were studied in the dog and rat.

TLOSRs were reduced by 55±8% after intragastric administration of AFPSiA at 14 μmol kg−1 and did not decrease further at higher doses. When evaluated 2 and 4 h after administration, the effect declined to 37±6 and 16±9%, respectively. Spontaneous swallowing was only significantly inhibited at 100 μmol kg−1.

The oral availability of AFPSiA was 52±17 and 71±4% in the dog and rat, respectively. A fraction of AFPSiA was oxidised to the corresponding sulphonate, (2R)‐(3‐amino‐2‐fluoropropyl)sulphonic acid (AFPSoA) after oral administration to the rat and dog.

In rat brain membranes, AFPSiA was found to have ten times higher affinity for rat brain GABAB (Ki=47±4.4 nM) compared to GABAA (Ki=430±46 nM) binding sites. The compound was a full agonist at human recombinant GABAB(1a,2) receptors (EC50=130±10 nM). In contrast, the metabolite AFPSoA was considerably more selective for binding to rat brain GABAA (Ki=37±3.1 nM) vs GABAB (Ki=6800±280 nM) receptors.

In the mouse, high doses (1–8 mmol kg−1) of AFPSiA induced a rapid and mild hypothermia followed by a profound and sustained hypothermia at the higher doses tested (6 and 8 mmol kg−1). This effect was unaffected by the selective GABAB receptor antagonist CGP62349. AFPSoA (1 and 2 mmol kg−1) produced transient and moderate hypothermia while the hypothermic response was considerably larger at 4 mmol kg−1.

It is concluded that AFPSiA inhibits but does not abolish TLOSRs in the dog. High doses of the compound induce hypothermia in the mouse, which probably is attributable to activation of the GABAA receptor. The latter effect may be caused both by AFPSiA and its oxidised sulphonic acid metabolite AFPSoA.

British Journal of Pharmacology (2005) 146, 89–97. doi:10.1038/sj.bjp.0706299
Electrophysiological and haemodynamic effects of endothelin ETA and ETB receptors in normal and ischaemic working rabbit hearts
Authors: McCabe Christopher , Hicks Martin N , Kane Kathleen A , Wainwright Cherry L
Published: June 2005

The aims of this study were to determine if endothelin‐1 (ET‐1) under normal and ischaemic conditions exhibits a direct arrhythmogenic effect that is independent of its ability to cause coronary vasoconstriction, and to determine the contribution of the ETA and ETB receptor subtype.

ETA/B (with ET‐1) and ETA (ET‐1 in the presence of BQ‐788) receptor activation resulted in a significant reduction in both epi‐ and endocardial monophasic action potential duration (MAPD90). ETA receptor activation reduced both epi‐ and endocardial effective refractory period (ERP). This MAPD90 and ERP shortening were associated with a reduction in coronary flow, myocardial contractility and induction of ventricular fibrillation (VF) during ERP measurement.

The ETB agonist sarafotoxin (S6c) had no marked, or concentration‐dependent, effect on MAPD90, ERP, myocardial contractility or induction of arrhythmias.

Neither ET‐1 nor S6c, given prior to coronary artery occlusion, significantly changed the ischaemia‐induced dispersion of MAPD90, ERP or the % incidence of VF.

In conclusion, neither ETA nor ETB receptor stimulation has a direct arrhythmogenic effect in isolated rabbit hearts under normal or ischaemic conditions. The ET‐1‐induced arrhythmogenic effect observed in nonischaemic hearts is likely to be the result of the associated coronary vasoconstriction caused by ETA receptor stimulation resulting in myocardial ischaemia.

British Journal of Pharmacology (2005) 146, 118–128. doi:10.1038/sj.bjp.0706304
Nonphotic entrainment of the circadian body temperature rhythm by the selective ORL1 receptor agonist W‐212393 in rats
Authors: Teshima Koji , Minoguchi Masanori , Tounai Sayuri , Ashimori Atsuyuki , Eguchi Junichi , Allen Charles N , Shibata Shigenobu
Published: June 2005

We synthesized a small‐molecule opioid receptor‐like 1 (ORL1) receptor agonist, 2‐{3‐[1‐((1R)‐acenaphthen‐1‐yl)piperidin‐4‐yl]‐2,3‐dihydro‐2‐oxo‐benzimidazol‐1‐yl}‐N‐methylacetamide (W‐212393), and investigated its effect on the circadian body temperature rhythm of rats.

W‐212393 has high affinity for ORL1 receptors in the rat cerebral cortex and human ORL1 receptors expressed in HEK293 cells with Ki values of 0.76 and 0.50 nM, respectively.

W‐212393 concentration‐dependently stimulated GTPγ35S binding and its efficacy was similar to nociceptin/orphanin FQ (N/OFQ), suggesting that W‐212393 is a full agonist at ORL1 receptors.

W‐212393 dose‐dependently occupied ORL1 receptors following intraventricular or intraperitoneal administration, suggesting that W‐212393 is a brain‐penetrating compound.

W‐212393 (100 nM) and N/OFQ (100 nM) significantly suppressed the activity of spontaneously firing rat suprachiasmatic nucleus neurons. These suppressive effects were blocked by an ORL1 receptor antagonist, J‐113397 (1 μM).

W‐212393 (3 mg kg−1, i.p.) induced a significant phase advance at circadian time 6 (CT6) and CT9, but not at other CTs. The magnitude of the W‐212393 (0.3–3 mg kg−1, i.p.)‐induced phase advance was dose‐dependent and greater than those produced by 8‐hydroxy‐2‐(di‐n‐propylamino)tetralin (0.3–3 mg kg−1, i.p.) or melatonin (0.3–3 mg kg−1, i.p.). The W‐212393 (3 mg kg−1, i.p.)‐induced phase advance was antagonized by J‐113397 (10 mg kg−1, i.p.).

W‐212393 (3 mg kg−1, i.p.) significantly accelerated the re‐entrainment of the body temperature rhythm to a 6 h advanced light–dark cycle.

These results indicate that activation of ORL1 receptors contributes to the circadian entrainment and W‐212393 may represent an interesting agent for the study of circadian rhythms.

British Journal of Pharmacology (2005) 146, 33–40. doi:10.1038/sj.bjp.0706311
The hypoglycaemic activity of fenugreek seed extract is mediated through the stimulation of an insulin signalling pathway
Authors: Vijayakumar Maleppillil Vavachan , Singh Sandeep , Chhipa Rishi Raj , Bhat Manoj Kumar
Published: June 2005

The in vivo hypoglycaemic activity of a dialysed fenugreek seed extract (FSE) was studied in alloxan (AXN)‐induced diabetic mice and found to be comparable to that of insulin (1.5 U kg−1). FSE also improved intraperitoneal glucose tolerance in normal mice.

The mechanism by which FSE attenuated hyperglycaemia was investigated in vitro. FSE stimulated glucose uptake in CHO‐HIRc‐mycGLUT4eGFP cells in a dose‐dependent manner. This effect was shown to be mediated by the translocation of glucose transporter 4 (GLUT4) from the intracellular space to the plasma membrane.

These effects of FSE on GLUT4 translocation and glucose uptake were inhibited by wortmannin, a phosphatidylinositol 3‐kinase (PI3‐K) inhibitor, and bisindolylmaleimide 1, a protein kinase C (PKC)‐specific inhibitor.

In vitro phosphorylation analysis revealed that, like insulin, FSE also induces tyrosine phosphorylation of a number of proteins including the insulin receptor, insulin receptor substrate 1 and p85 subunit of PI3‐K, in both 3T3‐L1 adipocytes and human hepatoma cells, HepG2. However, unlike insulin, FSE had no effect on protein kinase B (Akt) activation.

These results suggest that in vivo the hypoglycaemic effect of FSE is mediated, at least in part, by the activation of an insulin signalling pathway in adipocytes and liver cells.

British Journal of Pharmacology (2005) 146, 41–48. doi:10.1038/sj.bjp.0706312
Production risks and water use benefits of summer crop production on the south coast of Western Australia
Authors: Robertson M. J. , Gaydon D. , Hall D. J. M. , Hills A. , Penny S.
Published: June 2005

Summer crops grown during the summer fallow in a Mediterranean-type climate have the potential to produce out-of-season biomass and grain, increase water use, and reduce deep drainage. The potential effects of growing grain sorghum on components of the water balance, sorghum biomass and grain production, and yield of subsequent wheat crops were investigated by simulation using APSIM and long-term climate data from the Esperance district. Sorghum was simulated as part of 3 systems: (1) as an opportunity crop following wheat harvest, (2) as a fallow replacement after pasture removal and before entering a cropping phase, or (3) as a fallow replacement after a failed or waterlogged winter crop. Simulations were conducted for the period 1957–2003 at Myrup (mean annual rainfall 576 mm), Scaddan (408 mm), and Salmon Gums (346 mm). Sorghum was assumed to have a similar rooting depth to wheat. In order to gain confidence in using APSIM for these investigations, tests were initially conducted against field data involving summer and winter crops in sequence and measurements of soil water dynamics. Data sets also varied in summer rainfall, species (forage sorghum, grain sorghum, Japanese millet), and soil type (deep sand, and medium and shallow duplex).
Overall, the simulations showed that incorporation of a sorghum crop increased transpiration by 10–30 mm/year, made the soil profile drier by a similar amount at wheat sowing, and consequently reduced deep drainage by 3–25 mm/year, depending upon cropping system and location. Long-term average drainage results were dominated by large episodes in wet years. The increased transpiration from the summer crop, although reducing drainage in wet years, could not eliminate drainage. Following wheat yields were reduced by an average of 200–400 kg/ha, corresponding to a reduction of 10% at wetter and 30% at drier locations. In the 2 fallow replacement systems, sorghum biomass was produced in nearly every simulated season. However, averaged over all seasons, sorghum grain production was much less reliable comprising only 10–20% of biomass. In the opportunity system, sorghum produced biomass in only 1 in 3 seasons at Salmon Gums and Scaddan and 1 in 2 at Myrup. Grain was produced in 1 in 5 seasons at all 3 locations, underlining the riskiness of this opportunity niche for summer crops in the Esperance district.
Although summer cropping was shown to result in modest reductions in deep drainage, it also comes at a cost to wheat production. The largest effects on drainage and most reliable biomass production were seen in the systems where the summer crop was grown following pasture removal or a failed (waterlogged) winter crop. This research has also shown that recent farmer and researcher experiences of summer cropping are likely to be more favourably biased towards prospects for summer cropping than indicated by long-term simulations because of their longer-term perspective.
Relationship between sire estimated breeding values and the meat and eating quality of meat from their progeny grown on two planes of nutrition
Authors: Hopkins D. L. , Hegarty R. S. , Farrell T. C.
Published: June 2005

The meat of 140 female lambs was examined. These lambs were sired by 9 Poll Dorset sires (3 selected for growth, 3 for muscling and 3 control) and fed either a low or high plane of nutrition from birth to slaughter. All carcasses were electrically stimulated and portions of M. longissimus thoracis et lumborum (loin) aged for 5 days before freezing. Subsequently, 10 consumers tested each portion for eating quality traits. A portion of the same muscle from the opposing side of the carcass was divided into 3 sections and aged for either 1, 3 or 5 days and then used to measure shear force (objective tenderness). Portions of the M. semimembranosus (topside) were also aged for 3 or 5 days and subjected to shear testing. Low plane animals produced tougher loins (based on shear force). As ultimate pH increased, shear force of the loin increased for low plane animals, while for high plane animals there was no such effect. This latter group had significantly lower ultimate pH values in all 3 muscles tested. Plane of nutrition had the greatest effect on topside shear force with low plane lambs producing tougher topsides. As ultimate pH increased, the topsides became tougher and as expected ageing improved the tenderness. There was no effect of sire EBVs (estimated breeding values) on shear force or objective meat quality traits apart from loin lightness which increased as the EBV for post-weaning weight (PWWT) increased and intramuscular fat in the loin which decreased as sire EBV for post-weaning muscle depth (PEMD) increased. Plane of nutrition did not have a significant effect on eating quality attributes as assessed by consumers. There was, however, an effect of sire EBV for muscling (PEMD) on tenderness, juiciness, flavour and overall liking, such that increased EBV led to decreased scores for the sensory traits. The findings suggest selection of sires for increasing PEMD will have a detrimental affect on the eating quality of their progeny, but this will not be reflected in shear force values or other objective meat quality traits apart from intramuscular fat. The effects of a low plane of nutrition on eating quality were minimal and largely controlled by the use of best practice processing, but were evident for a number of meat quality traits.
Effect of sheep type on meat and eating quality of sheep meat
Authors: Hopkins D. L. , Walker P. J. , Thompson J. M. , Pethick D. W.
Published: June 2005

The effect of type of lambs and hoggets on eating quality was evaluated using the M. longissimus lumborum (LL) and the M. biceps femoris (BF) from 210 animals. The animals comprised 7 types as follows: Poll Dorset or White Suffolk × (Border Leicester × Merino) (second cross unweaned lambs, mixed sex, 3–5 months of age); Poll Dorset × (Border Leicester × Merino) (second cross weaned lambs, mixed sex, 9–12 months of age); Border Leicester × Merino (BLM; first cross weaned lambs, mixed sex, 9 months of age); Poll Dorset or White Suffolk × Merino (PDM; first cross weaned lambs, wethers, 12 months of age); Merino × Merino (weaned wether lambs, 9–12 months of age); Border Leicester × Merino (BLM; first cross hoggets, mixed sex, 20 months of age); and Poll Dorset or White Suffolk × Merino (PDM; first cross hoggets, wethers, 16 months of age). The animals were sourced from a number of different properties in New South Wales (NSW) (n = 120) and Victoria (n = 90). Each carcass was subjected to high voltage stimulation (700 V) within 1 h of slaughter. All meat was aged for 5 days before freezing and was subsequently tested by consumers on a 0–100 scale for a number of attributes after cooking using a grilling procedure. The LL from sucker lambs had the lightest colour (highest L* values) with the hoggets having the darkest colour in the NSW group with differences less apparent in the Victorian group. Muscle from first cross and Merino weaned lambs had consistently higher pH levels across the 3 muscles tested (LL; M. semimembranosus; M. semitendinosus) for the NSW group with no differences detected in the Victorian group. LL meat from second cross sucker and first cross (BLM and PDM) weaned lambs had the highest overall liking score, with that from second cross weaned lambs, BLM hoggets and Merino lambs scored as intermediate, while meat from the PDM hogget group had the lowest overall liking score. A similar outcome was found for the other sensory attributes with differences between types being lower for juiciness compared with overall liking scores but they were of a similar ranking. For the BF there was some re-ranking of the overall liking scores compared with the LL, with meat from suckers and first cross PDM lambs and hoggets being intermediate in score while second cross weaned lambs and first cross BLM lambs had the highest scores. The BF from hoggets (BLM) and Merino lambs were given the lowest scores. The lower juiciness score for sucker BF contributed to this change in ranking compared with the LL.
Modified atmosphere packaging improves retail display life of lamb cuts with variation between loin and knuckle
Authors: Channon H. A. , Baud S. R. , Walker P. J.
Published: June 2005

This study was conducted to determine the effect of electrical stimulation [control or stimulated (applied for 20 s using a constant current of 600 mA peak and maximum voltage of 550 V with a frequency of either 14 Hz or 10 Hz], ageing period (7, 21 or 35 days) and packaging method [modified atmosphere packaging (MAP) or overwrapped] on the retail display life of lamb [bone-in loin (M. longissimus thoracis et lumborum) chops and boneless leg steaks from the knuckle (M. quadriceps femoris)]. The colour and retail acceptability of lamb cuts were assessed both subjectively and objectively, using a chromameter, after 3 (midpoint of commercial retail display life; midpoint) and 5 (endpoint of commercial retail display life; endpoint) days for overwrapped product and at 5 (midpoint) and 9 (endpoint) days for MAP product. Retail display life of lamb (assessed both objectively and subjectively) was improved (P<0.001) by packaging lamb cuts into modified atmosphere compared with overwrapped lamb cuts. Electrical stimulation and length of ageing period before preparation into retail cuts did not influence colour or retail display life of lamb loin chops or leg steaks. Although the interaction of ageing period and packaging method were significant (P<0.001) for subjective colour, acceptability and retail grade of lamb loin chops and leg steaks at the midpoint of display life, these effects were inconsistent. This study highlighted that further work is necessary to determine potential means of improving the colour stability of lamb to enhance its retail display life, particularly cuts of the M. quadriceps femoris.
The impact of processing on sensory and objective measurements of sheep meat eating quality
Authors: Thompson J. M. , Hopkins D. L. , D'Souza D. N. , Walker P. J. , Baud S. R. , Pethick D. W.
Published: June 2005

The impact of processing factors on sheep meat eating quality was investigated in an experiment in which stimulation (stimulation and no stimulation), chilling rate (fast and slow chilling) and carcass suspension (tenderstretch and normally hung by Achilles tendon) treatments were overlaid on 80 lamb and 40 mutton carcasses processed over 2 days, at 2 different abattoirs. Within each carcass, 3 muscles (M. longissimus thoracics et lumborum, biceps femoris and serratus ventralis) were collected from both sides and aged for 2 of 3 ageing periods (2, 5 or 14 days), before sensory testing for tenderness, juiciness, like flavour and overall liking, using a consumer taste panel. Processing treatments of stimulation and chilling were variable in their effect on the rates of pH and temperature decline and temperature at pH 6 (temp@pH6), between the 4 slaughter groups. Therefore chilling rate and electrical stimulation were considered as tools by which temp@pH6 could be manipulated, rather than as treatment effects per se.
Age category (lamb or mutton) had the largest impact on tenderness score, followed by muscle, ageing and carcass suspension. There were significant interactions for tenderness and overall liking scores between muscle × ageing, age category × muscle and carcass suspension × muscle (P<0.05). The magnitude of the tenderstretch advantage in sensory scores was a function of temp@pH6. In normally hung carcasses, the highest sensory scores were evident at about 21°C temp@pH6, with a decrease in sensory scores at high (>30°C) or low (<10°C) temp@pH6. There was a tendency for sensory scores (particularly for the like flavour score) to decline for the biceps femoris when it was stored for extended periods (14 days).
Effects of animal age on the eating quality of sheep meat
Authors: Pethick D. W. , Hopkins D. L. , D'Souza D. N. , Thompson J. M. , Walker P. J.
Published: June 2005

The aim of this work was to test the effects of animal age on consumer perceptions of sheep meat quality. Experiment 1 tested eating quality scores (tenderness, liking of flavour, juiciness and overall liking) derived from untrained consumers of grilled M. longissimus lumborum (LL) or M. biceps femoris (BF) derived from Merino ewes ranging from 8.5 to 68.5 months of age. The ewes were derived from one farm and all received a pelleted diet (60% hay, 30% lupin grain and 10% barley grain) that sustained growth between 118 and 173 g/day for at least 22 days pre-slaughter. In experiment 2 consumer testing of grilled LL and roasted BF and M. semimembranosis (SM) was conducted on a commercial line of 12-month-old White Suffolk × Merino lambs (0 erupted incisor teeth) v. a line of Merino yearling sheep about 22 months old (with either 2 or 4 erupted incisor teeth). The results of experiment 1 showed a significant effect of muscle (LL>BF, P<0.001) and a cubic effect of animal age on the consumer scores for grilled steaks. The cubic relationship was due to meat from lamb (8.5 months) and hogget (20 months) having higher scores than those of older animals. There was a close relationship between the objective measures of tenderness and the consumer tenderness score (r2 = 0.53, P<0.001). Results of experiment 2 indicated no significant difference between the grilled LL for the crossbred lamb and 22-month-old (2–4 teeth) Merino yearling sheep. However, the consumer scores for the roasted BF and SM were significantly depressed in the 2–4 tooth yearling Merino categories. In conclusion, this work clearly underpins the current Australian definition of lamb, lamb having better eating-quality attributes than older animals with fully erupted permanent incisor teeth, particularly in muscles from across the carcass. However, this work also highlights the eating quality attributes of older sheep (6 or more permanent incisor teeth) particularly for the LL, and suggests that negative influences of flavour associated with older sheep meat are minimal when the product is served in the absence of subcutaneous and intermuscular fat. Finally, the results suggest the possibility of a new ‘yearling’ sheep meat category based on animals in the 2–4-tooth dentition category.
New electrical stimulation technologies for sheep carcasses
New electrical stimulation technologies for sheep carcasses
Authors: Shaw F. D. , Baud S. R. , Richards I. , Pethick D. W. , Walker P. J. , Thompson J. M.
Published: June 2005

High voltage electrical stimulation applied to the lamb carcass at the end of the dressing procedure often leads to an improvement in overall product quality by reducing the incidence of toughness. It would be advantageous if the same results could be consistently achieved with the use of lower, safer, voltages — medium voltage electrical stimulation. Experiments were conducted to determine the effect of medium voltage electrical stimulation applied to wool-on carcasses on meat quality as assessed using the Sheep Meat Eating Quality protocols. A further experiment examined the interaction of electrical stimulation and meat aging time on the consumer acceptance of lamb meat. In the first experiment, 3 treatments: control (non-stimulated), medium voltage electrical stimulation (applied to the wool-on carcass) and high voltage electrical stimulation (applied at the completion of dressing) were examined. Samples of the loin (LTL) and rump (GM) muscles were evaluated by consumers using Sheep Meat Eating Quality protocols. For both muscles, the consumers gave higher scores for tenderness, juiciness, flavour and overall acceptability to the stimulated product (P<0.001). There were no statistically significant differences between the 2 stimulation treatments. The second experiment was conducted at a commercial lamb-processing abattoir that had installed a prototype automated electrode system designed to work at chain speed. Lambs received either no stimulation (control), low current medium voltage electrical stimulation (constant current 300 mA peak, 15 Hz, maximum voltage 550 V peak) or high current medium voltage electrical stimulation (constant current 600 mA peak, 15 Hz, maximum voltage 550 V peak) immediately after sticking. Electrical stimulation improved both the objective and sensory (Sheep Meat Eating Quality) eating quality attributes of lamb loin muscle when assessed following 2 days of ageing. When expressed according to consumer satisfaction rating, 30, 37 and 70% of the loins receiving low, high or no electrical stimulation, respectively, were rated as unsatisfactory at 2 days of ageing. At 4 days of ageing no loins from carcasses in the low stimulation treatment were rated by consumers to be unsatisfactory (P<0.05) compared with either non-stimulated (40%) or high-stimulated loins (35%). With respect to the effects of aging meat, electrical stimulation improved the consumer score at 2 days post-stunning by 8.9 and 4.7 points for tenderness and overall liking, respectively. Further linear improvements due to aging were similar for both electrical stimulation and unstimulated products. Under conditions of no electrical stimulation used in this experiment, 10 days aging results in tenderness and overall liking scores greater than 60 and with ES similar scores are achieved in 5 days. Consumer scores over 60 greatly reduce the chance of meat being classified as unsatisfactory.
Lamb and sheep meat eating quality — industry and scientific issues and the need for integrated research
Authors: Russell B. C. , McAlister G. , Ross I. S. , Pethick D. W.
Published: June 2005

This paper provides an introduction to the special edition of the Australian Journal of Experimental Agriculture dedicated to an integrated research program aimed at understanding the critical control points which determine the consumer defined eating quality of Australian lamb and sheep meat. The reasons for a general approach in the research is outlined.
The effect of design and demographic factors on consumer sensory scores
Authors: Thompson J. M. , Pleasants A. B. , Pethick D. W.
Published: June 2005

The importance of design and demographic effects on sensory scores for tenderness, juiciness, like flavour and overall liking scores was examined using a dataset of 24 840 untrained consumer tastings on 2484 grilled sheep meat samples, from 4140 consumers. These samples were tasted as part of 23 separate taste panels, each made up of 9 separate sessions each comprising of 20 different consumers. Before undertaking the tastings, each consumer provided demographic details detailing age class, gender, occupation, frequency of eating meat, number of adults and children living in the household, their appreciation of meat, preferred degree of doneness and income category. Taste panel had a significant (P<0.001) effect on the 4 sensory scores, which in part would have reflected experimental effects on sensory scores. The experimental sample was still highly significant (P<0.001) even though, effect of session and taster, nested within taste panel, were also significant (P<0.001) for all sensory attributes. Demographic effects showed that age, gender and number of adults in the household had significant (P<0.05) effects on juiciness scores, but not for tenderness, like flavour and overall liking scores (P>0.05). All 4 sensory scores were affected (P<0.05) by consumer appreciation of meat, where those who enjoyed red meat and considered it an important part of their life gave sensory scores 2–4 units greater (on a 100-point scale) than consumers’ who were indifferent to red meat. Those consumers who preferred medium to well-done meat gave sensory scores that were 2 units higher than consumers who preferred medium, or rare meat. All other demographic effects were not significant (P>0.05) for any of the 4 sensory scores. It was concluded that demographic effects had only a minor impact on sensory scores. This inferred that the need to balance consumer demographics for sensory panels was relatively unimportant.
A model relating a function of tenderness, juiciness, flavour and overall liking to the eating quality of sheep meat
Authors: Pleasants A. B. , Thompson J.M. , Pethick D.W.
Published: June 2005

A probabilistic model of consumer perception of sheep meat eating quality is constructed on the basis of a sensory score derived from consumer evaluation of tenderness, juiciness, flavour and overall liking. The model includes consideration of the variability of the sensory score within a mob, the probability that meat with a given sensory score will be perceived by the consumer as correctly classified, and the distribution of the average sensory score within an eating quality grade. Based on this information the model can calculate the frequency with which sheep meat given a sensory score that will fail to meet the consumer expectation of the allocated eating quality grade. The model provides a basis for integrating the information gathered on sheep meat eating quality to formulate a method of classification and to quantify the reliability of this classification. This information can be applied in a variety of ways to evaluate the efficacy, financial or otherwise, of a retailer adopting a given sheep meat eating quality classification based on the nominated eating quality score.
Tareena Billabong - a palaeolimnological history of an ever-changing wetland, Chowilla Floodplain, lower Murray - Darling Basin, Australia
Authors: Gell Peter A. , Bulpin Sorell , Wallbrink Peter , Hancock Gary , Bickford Sophie
Published: June 2005

A 427-cm sediment core was extracted from Tareena Billabong, a Murray River floodplain wetland in the extreme south-west of New South Wales, Australia. Analysis of fossil diatoms and pollen, sediment 210Pb and 137Cs profiles and radiocarbon and luminescence dating reveal that Tareena Billabong has undergone substantial environmental change in its ~5000-year history. Shortly after its formation, the billabong was a freshwater lagoon with a diatom flora dominated by Synedra ulna and Planothidium lanceolatum. An increase in Aulacoseira granulata, a river plankton dominant today, reflects two phases of increased connectivity with the Murray River in the mid to late Holocene. A shift to lagoonal taxa after ~3000 years BP is attributed to water balance and river-flow changes, possibly associated with regional climate change. Importantly, it appears to have undergone an extended phase of increasing turbidity, and possibly wetland salinity, commencing ~3000 years BP. Sedimentation increased at least 15-fold in the European phase. Billabong salinity increased markedly soon after European settlement, reaching a peak in the late 1800s AD. While regulation then increased the degree of connection between the billabong with the River in the 1920s AD, salinity levels remained high. Increased salinity is revealed by increases in the diatom taxa Amphora spp., Cyclotella meneghiniana, Gyrosigma acuminatum, Planothidium delicatulum and Tryblionella hungarica and by declines in Casuarinaceae, Eucalyptus, Myriophyllum and Cyperaceae pollen. Tareena Billabong was subjected to considerable environmental pressures from the early stages of European settlement in terms of sediment load, hydrological change and salinity.
Feeding habits of the sandskate Psammobatis extenta (Garman, 1913): sources of variation in dietary composition
Authors: Braccini J. Matías , Perez Jorge E.
Published: June 2005

Understanding the variation in the diet of skates is crucial for determining their roles in marine ecosystems. The diet of 458 sandskates, Psammobatis extenta, from Puerto Quequén, Argentina was quantified to determine whether there was geographical, sexual, ontogenetic, and/or seasonal variation in dietary composition. Cumulative prey-diversity curves reached a stable level at ~30 stomachs and thus the sample size was large enough to describe the overall diet of the sandskate. The diet comprised a variety of small invertebrates, suggesting that the sandskate is a secondary consumer (trophic level of 3.5). The most important prey items were gammarids, shrimps and, to a lesser extent, polychaete worms. A significant correlation was found between the diets of sandskates from south-eastern Brazil and Puerto Quequén, suggesting that in both locations they used similar resources and would have similar ecological roles. No difference was found between the diets of males and females, but ontogenetic and seasonal patterns were detected. Small sandskates preyed largely on gammarids and shrimps but consumed fewer polychaetes and brachyurans than larger individuals. In summer and winter, the most important prey item by number was gammarids, whereas the consumption of shrimps peaked in autumn. This ontogenetic and seasonal pattern indicates that large and small sandskates are versatile predators that can shift their diets in response to prey abundance.
Movement and juvenile recruitment of mangrove jack, Lutjanus argentimaculatus (Forsskål), in northern Australia
Authors: Russell D. J. , McDougall A. J.
Published: June 2005

Lutjanus argentimaculatus, tagged and released in coastal rivers and estuaries, were found to have made inter- and intra-riverine, coastal and offshore movements. A small proportion of the recaptures made offshore movements to reef habitats of up to 315 km and these recaptures were fish that were at liberty, on average, more than twice as long as those fish that had made intra-riverine movements. Most juvenile fish <400-mm length to caudal fork (LCF) resident in rivers were recaptured less than a kilometre from where they were released. The proportion of fish making sizeable movements increased with increasing recapture size, with about of 20% of larger fish (400–500-mm LCF) making offshore, inter-riverine or coastal movements. Larger fish were primarily caught offshore, whereas smaller fish <~338-mm LCF were exclusively caught in estuarine and freshwater habitats. Recruitment of juveniles into estuarine and lower freshwater riverine habitats occurred from about February. There was temporal variability of recruitment of mangrove jack into some river systems and their relative abundance within the river system was inversely proportional to the distance from the sea. Overfishing of juveniles when they are concentrated in inshore areas could have adverse implications for mangrove jack stocks.
Inspired Oxygen Fraction of 0.8 Does Not Attenuate Postoperative Nausea and Vomiting after Strabismus Surgery
Authors: Treschan Tanja A. , Zimmer Christian , Nass Christoph , Stegen Bernd , Esser Joachim , Peters Jürgen
Published: June 2005

Background

Postoperative nausea and vomiting (PONV) is a distressing problem after strabismus surgery. An inspired oxygen fraction has been reported to decrease PONV in patients after colon resection and to be more effective than ondansetron after gynecologic laparoscopy. Therefore, in a randomized, prospective, placebo-controlled study, the authors tested whether an inspired oxygen fraction of 0.8 decreases PONV in patients undergoing strabismus surgery and whether oxygen is more effective than ondansetron.

Methods

With approval of the authors' institutional review board, 210 patients were randomly assigned to receive one of three treatments: (1) 30% inspired oxygen in air plus intravenous administration of saline, (2) 80% inspired oxygen in air plus intravenous administration of saline, or (3) 30% inspired oxygen in air plus 75 microg/kg ondansetron intravenously during induction. General anesthesia was standardized and included etomidate, alfentanil, and mivacurium for induction and sevoflurane for maintenance. PONV was evaluated 6 and 24 h postoperatively by an investigator unaware of treatment assignment.

Results

Overall postoperative incidence of nausea and vomiting was 41% for inspired oxygen fraction of 0.3 plus placebo, 38% for inspired oxygen fraction of 0.8 plus placebo, and 28% for inspired oxygen fraction of 0.3 plus ondansetron, respectively (P = 0.279). Therefore, there was no statistically significant difference of PONV incidence among groups.

Conclusions

An inspired oxygen fraction of 0.8 during general anesthesia with sevoflurane does not decrease PONV in patients undergoing strabismus repair. Ondansetron also did not significantly decrease PONV in our study setting.
Attenuated Brain Response to Auditory Word Stimulation with Sevoflurane
Authors: Kerssens Chantal , Hamann Stephan , Peltier Scott , Hu Xiaoping P. , Byas-Smith Michael G. , Sebel Peter S.
Published: June 2005

Background

Functional magnetic resonance imaging offers a compelling, new perspective on altered brain function but is sparsely used in studies of anesthetic effect. To examine effects on verbal memory encoding, the authors imaged human brain response to auditory word stimulation using functional magnetic resonance imaging at different concentrations of an agent not previously studied, and tested memory after recovery.

Methods

Six male volunteers were studied breathing 0.0, 2.0, and 1.0% end-tidal sevoflurane (awake, deep, and light states, respectively) via laryngeal mask. In each condition, they heard 15 two-syllable English nouns via closed headphones. Each word was repeated 15 times (1/s), followed by 15 s of rest. Blood oxygenation level-dependent brain activations during blocks of stimulation versus rest were assessed with a 3-T Siemens Trio scanner and a 20-voxel spatial extent threshold. Memory was tested approximately 1.5 h after recovery with an auditory recognition task (chance performance = 33% correct).

Results

Scans showed widespread activations (P < 0.005, uncorrected) in the awake state, including bilateral superior temporal, frontal, and parietal cortex, right occipital cortex, bilateral thalamus, striatum, hippocampus, and cerebellum; more limited activations in the light state (bilateral superior temporal gyrus, right thalamus, bilateral parietal cortex, left frontal cortex, and right occipital cortex); and no significant auditory-related activation in the deep state. During recognition testing, subjects correctly selected 77 +/- 12% of words presented while they were awake as "old," versus 32 +/- 15 and 42 +/- 8% (P < 0.01) correct for the light and deep stages, respectively.

Conclusions

Sevoflurane induces dose-dependent suppression of auditory blood oxygenation level-dependent signals, which likely limits the ability of words to be processed during anesthesia and compromises memory.
Effect of Intraoperative Fluid Management on Outcome after Intraabdominal Surgery
Authors: Nisanevich Vadim , Felsenstein Itamar , Almogy Gidon , Weissman Charles , Einav Sharon , Matot Idit
Published: June 2005

Background

The debate over the correct perioperative fluid management is unresolved.

Methods

The impact of two intraoperative fluid regimes on postoperative outcome was prospectively evaluated in 152 patients with an American Society of Anesthesiologists physical status of I-III who were undergoing elective intraabdominal surgery. Patients were randomly assigned to receive intraoperatively either liberal (liberal protocol group [LPG], n = 75; bolus of 10 ml/kg followed by 12 ml x kg(-1) x h(-1)) or restrictive (restrictive protocol group [RPG], n = 77; 4 ml x kg(-1) x h(-1)) amounts of lactated Ringer's solution. The primary endpoint was the number of patients who died or experienced complications. The secondary endpoints included time to initial passage of flatus and feces, duration of hospital stay, and changes in body weight, hematocrit, and albumin serum concentration in the first 3 postoperative days.

Results

The number of patients with complications was lower in the RPG (P = 0.046). Patients in the LPG passed flatus and feces significantly later (flatus, median [range]: 4 [3-7] days in the LPG vs. 3 [2-7] days in the RPG; P < 0.001; feces: 6 [4-9] days in the LPG vs. 4 [3-9] days in the RPG; P < 0.001), and their postoperative hospital stay was significantly longer (9 [7-24] days in the LPG vs. 8 [6-21] days in the RPG; P = 0.01). Significantly larger increases in body weight were observed in the LPG compared with the RPG (P < 0.01). In the first 3 postoperative days, hematocrit and albumin concentrations were significantly higher in the RPG compared with the LPG.

Conclusions

In patients undergoing elective intraabdominal surgery, intraoperative use of restrictive fluid management may be advantageous because it reduces postoperative morbidity and shortens hospital stay.
Anaphylactic Shock
Authors: Dewachter Pascale , Jouan-Hureaux Valérie , Franck Patricia , Menu Patrick , de Talancé Nicole , Zannad Faiez , Laxenaire Marie-Claire , Longrois Dan , Mertes Paul Michel
Published: June 2005

Background

The pathophysiology of anaphylactic shock during anesthesia is incompletely characterized. It is described as distributive by analogy with septic shock (anaerobic metabolism, high tissue oxygen pressure [Ptio2] values). The Ptio2 profile and its metabolic consequences during anaphylaxis are not known.

Methods

Ovalbumin-sensitized anaphylactic shock rats (n = 11) were compared to nicardipine-induced hypotension rats (n = 12) for systemic hemodynamics, Ptio2, sympathetic nervous system activation, skeletal muscle blood flow, and interstitial lactate and pyruvate concentrations using combined microdialysis and polarographic Clark-type oxygen probes.

Results

In both groups, the time course and the magnitude of arterial hypotension were similar. The ovalbumin group but not the nicardipine group displayed decreased skeletal muscle blood flow (from 45 +/- 6.2 ml x 100 g(-1) x min(-1) to 24.3 +/- 5 ml x 100 g(-1) x min(-1); P < 0.0001) and Ptio2 values (from 42 +/- 5 to 5 +/- 2; P < 0.0001). The ovalbumin group had more intense sympathetic nervous system activation with higher plasma epinephrine and interstitial norepinephrine concentrations. For the ovalbumin group, there was skeletal muscle anaerobic metabolism (lactate concentration increased from 0.446 +/- 0.105 to 1.741 +/- 0.459 mm; P < 0.05) and substrate depletion (pyruvate concentration decreased from 0.034 +/- 0.01 mm to 0.006 +/- 0.002 mm; P < 0.05) leading to increased interstitial lactate/pyruvate ratios (from 17 +/- 6 to 311 +/- 115; P < 0.05).

Conclusions

This profile suggests decreased skeletal muscle blood flow and oxygen delivery. Persistent energy consumption results in decreased Ptio2 and substrate depletion through anaerobic glycolysis leading to complete failure of cellular energy production. This could explain rapid organ dysfunction and resuscitation difficulties.