bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth and development of the veliger larvae and juveniles of Polinices pulchellus (Gastropoda: Naticidae)
Authors: Kingsley-Smith Peter R. , A. Richardson Christopher , Seed Raymond
Published: February 2005

Adult Polinices pulchellus were collected from the field and held in aquaria under ambient conditions. Egg collars laid by P. pulchellus were cultured at 14°C and 20°C and larval development after hatching was documented photographically. Planktotrophic Polinices pulchellus veligers hatched from egg collars cultured at 20°C after nine to ten days and after 14 to 15 days at 14°C. Veligers spent most of their time close to the water surface and began feeding within one hour of hatching. Repeated attempts to raise larvae to metamorphic competency at 14°C were unsuccessful. Morphological changes, most notably in the colour and size of the velum and foot, were observed in larvae raised at 20°C. During the first 25 days of larval development the velum broadened and bifurcated into four velar arms, the distal regions of which acquired a deep red coloration. By day 40 the foot had increased considerably in size and the degree of black pigmentation. By day 45 pediveligers were competent to metamorphose to the juvenile stage. Exposure to sediment from the adult habitat induced metamorphosis, larvae lost their vela and became benthic juveniles. Within three days of metamorphosis, juvenile snails drilled the bivalve Lasaea adansoni (∼2 mm), later drilled Cerastoderma edule (∼4 mm), and displayed cannibalistic behaviour. Larvae survived for ∼6 months in the absence of a suitable settlement cue.
First recorded specimen of the giant squid Architeuthis sp. in Portugal
Authors: Pereira João , Rosa Rui , Moreno Ana , Henriques Miguel , Sendão João , Borges Teresa C.
Published: February 2005

The first occurrence of a giant squid Architeuthis sp. specimen in Portuguese waters is noted and another reference set of biological and biometrical data provided which may in future be used in conjunction with others to further elucidate important aspects of the identity, biology and ecology of the species. The fact that the specimen is a male is relevant, since males have been much less frequent in the reports in the scientific literature than have females. Additionally, this is the most southerly report of a male known to have occurred in the Atlantic Ocean.
Allozyme analysis of geographical and seasonal variation of Illex coindetii (Cephalopoda: Ommastrephidae) from central Mediterranean and Iberian Atlantic
Authors: Martínez P. , Belcari P. , Sanjuan A. , Guerra A.
Published: February 2005

Previous morphological studies of Illex coindetii from the Mediterranean have shown both juvenile and mature individuals all year round suggesting an homogeneous population pattern, however, seasonal spawning variation seems to exist varying with geographical area. Present work analysed 240 individuals from the northern Tyrrhenian and Atlantic Iberian waters at the four year-round seasons using 33 presumptive enzyme-coding loci to compare geographical and temporal variances. Genetic variability was low (Ho=0·02–0·04). Moderate variation at some loci was found due to both temporal and geographical factors (12% of total genetic variance) and to temporal variance (FST=0·004–0·015). Unweighted pair-group method using arithmetric averages (UPGMA) and Multidimensional scaling–minimum spanning tree (MDS–MST) analyses after Cavalli-Sforza & Edwards (1967) chord genetic distances showed the summer Italian and the spring Atlantic samples as the most divergent among the whole.
The role of climate in determining the temporal variation in abundance, recruitment and growth of sole Solea solea in the Bristol Channel
Authors: Henderson P.A. , Seaby R.M.
Published: February 2005

Using a 24-year time series of monthly samples, the factors correlated with long-term variation in the abundance and growth of sole, Solea solea, in Bridgwater Bay in the Bristol Channel, England are identified. This bay offers shallow estuarine habitat used by sole as a nursery area. Sole first enter the bay in July when 2–3 months old and after a residence of 4–5 months, the majority migrate offshore at the beginning of winter to return the following April. By three years of age most have left the bay never to return although occasional large fish up to 480 mm in length are caught. Sole were found to be highly seasonal in their growth and only increased in length during the months of May to August inclusive. In recent years, there has been an approximately exponential increase in sole abundance that is highly positively correlated with seawater temperature during the early part of the season. The average length of fish in September, at the end of their first growing season, showed significant between year variation, ranging from 65·3 mm in 1989 to 79·8 mm in 2003. This variation was positively correlated with the North Atlantic Oscillation (NAO) winter index for the winter prior to their birth. Between year recruitment variation is correlated with both water temperature and the rate of growth. High temperatures allow faster development and a positive NAO index increases productivity and offers more food. Both of these positive influences act to reduce mortality resulting in stronger year-classes. No relationships between sole and other fish and macro-crustaceans living in the nursery were identified.
Distant effect of assimilation of moored currents into a model of coastal wind‐driven circulation off Oregon
Authors: Kurapov Alexander L. , Allen J. S. , Egbert G. D. , Miller R. N. , Kosro P. M. , Levine M. , Boyd T.
Published: February 2005

An optimal interpolation (OI) sequential algorithm is implemented for a three‐dimensional primitive equation model to assimilate current measurements from acoustic Doppler profilers moored on the Oregon shelf as a part of the Coastal Ocean Advances in Shelf Transport (COAST) upwelling experiment (May–August 2001). A stationary estimate of the forecast error covariance required by the OI is computed based on the error covariance in the model solution not constrained by data assimilation. Lagged model error covariances are used to account for the effect of previously assimilated data. The forecast error covariance has a shorter alongshore spatial scale than the model error covariance unconstrained by the data, as an effect of propagating dynamical modes. Assimilation of currents from one or two of the moorings located on the path of the upwelling jet helps to improve the model data rms error and correlation at the mooring sites located at an alongshore distance of 90 km, south or north from the assimilation sites. The coastal jet is deflected offshore over Heceta Bank, and assimilation of data from an inner‐shelf mooring in the jet separation zone does not help to improve prediction in the far field. Larger improvements are obtained for the first part of the study period (yeardays 146–190). In the second part (days 191–237) the geometry of our limited area model possibly limits prediction accuracy. In numerical experiments involving assimilation of data from only one mooring the actual and expected rms error improvements are compared, providing a consistency test for the forecast error covariance.
A study of wave effects on wind stress over the ocean in a fetch‐limited case
Authors: Pan Jiayi , Wang David W. , Hwang Paul A.
Published: February 2005

A field experiment was conducted for collecting three‐dimensional wind, wave, and air‐sea environmental data off the coast of Louisiana in the Gulf of Mexico in the mixed sea state of a wind sea limited by fetch and with swell propagating against the wind direction. Two methods, the inertial dissipation (ID) and eddy correlation (EC), are used to calculate wind stress. The results show that under the fetch‐limited condition, the EC wind stress is greater than the ID stress. This difference is found to be correlated with the counter‐wind swell. The swell‐related drag coefficient is computed from the wind stress difference between the ID and EC methods. An empirical formula is constructed for the swell‐related drag coefficient with a regression coefficient of 0.71. The swell‐related drag coefficient is proportional to the swell steepness (kpHs) and inversely proportional to the ratio of the wind speed and the swell peak phase speed (U10/Cp).
Imaging and quantification of gas hydrate and free gas at the Storegga slide offshore Norway
Authors: Zillmer M. , Reston T. , Leythaeuser T. , Flueh E. R.
Published: February 2005

Wide–angle reflection seismic experiments were performed at the Storegga slide offshore Norway in 2002 with the goal to quantify the amount of gas hydrate and free gas in the sediment. Twenty‐two stations with Ocean Bottom Hydrophones (OBH) and Seismometers (OBS) were deployed for a 2D and a 3D experiment. Kirchhoff depth migration is used to transform the seismic wide–angle data into images of the sediment layers and to obtain P wave velocity–depth functions. The gas hydrate and free gas saturations are estimated from the elastic properties of the sediment on the basis of the Frenkel–Gassmann equations. There is 5–15% gas hydrate in the pore space of the sediment in the gas hydrate stability zone (GHSZ). The free gas saturation takes the value of 0.8% for a homogeneous distribution of gas in the pore water and 7% for the model of a patchy gas distribution.
Regional atmospheric response to tropical Pacific SST perturbations
Authors: Katsafados P. , Papadopoulos A. , Kallos G.
Published: February 2005

An extended domain limited area model was implemented for seasonal‐range simulations to assess the effect of tropical Pacific SST perturbations on weather patterns over Europe and Mediterranean. The experimental method consisted of Skiron/Eta model integrations with coarse and fine grid increment using artificially‐modified as well as analysis SST forcing. The selected period was August–October 1997. Model simulations with coarse grid increment produced a weak signal in the precipitation pattern and the synoptic scale circulation over Europe, implying a damping of the North Atlantic atmospheric response to the tropical Pacific SST perturbation. Fine resolution experiments suggested an amplified dynamic response providing a direct link between tropical Pacific SST and North Atlantic synoptic circulation. The output signal is mainly attributed to the effective representation of the regional/mesoscale atmospheric features due to the model implementation with a fine mesh grid.
Four dimensional mapping of tracer channelization in subhorizontal bedrock fractures using surface ground penetrating radar
Authors: Talley Jennifer , Baker Gregory S. , Becker Matthew W. , Beyrle Nicholas
Published: February 2005

To observe flow channeling in situ, surface ground‐penetrating radar (GPR) was used to detect a saline tracer moving through a sub‐horizontal bedrock fracture. The tracer is mapped using amplitude variations resulting from the significant difference in electromagnetic properties between the tracer and natural ground water within the fracture. Results show that hydrogeophysical investigations using GPR can successfully image tracer movement in a variety of flow configurations in three spatial dimensions through time (hence 4D). Observed tracer travel paths demonstrated meter‐scale spatial variability that may be attributed to heterogeneity in fracture aperture.
A model for the diffuse attenuation coefficient of downwelling irradiance
Authors: Lee Zhong‐Ping , Du Ke‐Ping , Arnone Robert
Published: February 2005

The diffuse attenuation coefficient for downwelling irradiance (Kd) is an important parameter for ocean studies. For the vast ocean the only feasible means to get fine‐scale measurements of Kd is by ocean color remote sensing. At present, values of Kd from remote sensing are estimated using empirical algorithms. Such an approach is insufficient to provide an understanding regarding the variation of Kd and contains large uncertainties in the derived values. In this study a semianalytical model for Kd is developed based on the radiative transfer equation, with values of the model parameters derived from Hydrolight simulations using the averaged particle phase function. The model is further tested with data simulated using significantly different particle phase functions, and the modeled Kd are found matching Hydrolight Kd very well (∼2% average error and ∼12% maximum error). Such a model provides an improved interpretation about the variation of Kd and a basis to more accurately determine Kd (especially using data from remote sensing).
Influence of tides on sea ice in the Weddell Sea: Investigations with a high‐resolution dynamic‐thermodynamic sea ice model
Authors: Koentopp M. , Eisen O. , Kottmeier C. , Padman L. , Lemke P.
Published: February 2005

The effects of tides on the seasonal fluctuations and regional differences of the sea ice cover in the Weddell Sea are investigated using a dynamic‐thermodynamic sea ice model operating at high temporal and spatial resolution. Tidal currents add a highly variable stress force at the ice‐water interface. They are derived from an eight‐constituent barotropic, ocean‐only, tidal model. Thermodynamics are calculated for seven ice classes plus open water; dynamics consider an averaged ice class and open water only. Results from runs of the sea ice model with and without the additional tidal stress demonstrate that tidal currents alter the local and, to lesser extent, basin‐wide evolution of sea ice. The tidal currents reduce the expansion of the ice cover, mostly cause a speed up of the retreat, and lead to a smaller minimum ice extent. The most significant local differences between the two model simulations are found in tidally active regions over the continental shelf breaks of the western Weddell Sea, in front of Filchner‐Ronne Ice Shelf, and offshore Dronning Maud Land.
Satellite observations of mesoscale ocean features and copropagating atmospheric surface fields in the tropical belt
Authors: Small Richard Justin , Xie Shang‐Ping , Hafner Jan
Published: February 2005

Recent studies of air‐sea interaction using satellite data have shown a high positive correlation between wind speed and sea surface temperature (SST) over mesoscale ocean features in certain frontal regions. The aim of this study is to determine to what extent mesoscale ocean dynamics modifies the surface wind speed over the global tropics between 40°S and 40°N. Cross‐spectral and linear regression methods are used to identify robust relationships between ocean and atmospheric variables. The ocean dynamical features, measured by their sea surface height anomaly (SSHA), affect SST in a manner consistent with advection of the mean temperature gradient by anomalous currents. The response varies from 0.2°C of SST per cm of SSHA near the equator to 0.05°C cm−1 at higher latitudes. A remarkably consistent in‐phase relationship between SST and wind speed is found over the complete domain. Wind speed response varied from 0.5 to 1.5 ms−1 per °C of SST change. This in‐phase response of wind speed is consistent with previous studies suggesting that the SST variations cause changes in the vertical exchange of momentum and in the pressure gradient, which alter the wind speed.
The dextromethorphan analog dimemorfan attenuates kainate‐induced seizures via σ1 receptor activation: comparison with the effects of dextromethorphan
Authors: Shin Eun‐Joo , Nah Seung‐Yeol , Kim Won‐Ki , Ko Kwang Ho , Jhoo Wang‐Kee , Lim Yong‐Kwang , Cha Joo Young , Chen Chieh‐Fu , Kim Hyoung‐Chun
Published: February 2005

In a previous study, we demonstrated that a dextromethorphan analog, dimemorfan, has neuroprotective effects.

Dextromethorphan and dimemorfan are high‐affinity ligands at σ1 receptors. Dextromethorphan has moderate affinities for phencyclidine sites, while dimemorfan has very low affinities for such sites, suggesting that these sites are not essential for the anticonvulsant actions of dimemorfan.

Kainate (KA) administration (10 mg kg−1, i.p.) produced robust convulsions lasting 4–6 h in rats. Pre‐treatment with dimemorfan (12 or 24 mg kg−1) reduced seizures in a dose‐dependent manner. Dimemorfan pre‐treatment also attenuated the KA‐induced increases in c‐fos/c‐jun expression, activator protein (AP)‐1 DNA‐binding activity, and loss of cells in the CA1 and CA3 fields of the hippocampus. These effects of dimemorfan were comparable to those of dextromethorphan.

The anticonvulsant action of dextromethorphan or dimemorfan was significantly counteracted by a selective σ1 receptor antagonist BD 1047, suggesting that the anticonvulsant action of dextromethorphan or dimemorfan is, at least in part, related to σ1 receptor‐activated modulation of AP‐1 transcription factors.

We asked whether dimemorfan produces the behavioral side effects seen with dextromethorphan or dextrorphan (a phencyclidine‐like metabolite of dextromethorphan). Conditioned place preference and circling behaviors were significantly increased in mice treated with phencyclidine, dextrorphan or dextromethorphan, while mice treated with dimemorfan showed no behavioral side effects.

Our results suggest that dimemorfan is equipotent to dextromethorphan in preventing KA‐induced seizures, while it may lack behavioral effects, such as psychotomimetic reactions.

British Journal of Pharmacology (2005) 144, 908–918. doi:10.1038/sj.bjp.0705998
ClC‐3 chloride channel is upregulated by hypertrophy and inflammation in rat and canine pulmonary artery
Authors: Dai Yan‐Ping , Bongalon Shaner , Hatton William J , Hume Joseph R , Yamboliev Ilia A
Published: February 2005

Cl− channels have been implicated in essential cellular functions including volume regulation, progression of cell cycle, cell proliferation and contraction, but the physiological functions of the ClC‐3 channel are controversial. We tested the hypothesis that the ClC‐3 gene (ClCn‐3) is upregulated in hypertensive pulmonary arteries of monocrotaline‐treated rats, and upregulated ClC‐3 channel aids viability of pulmonary artery smooth muscle cells (PASMCs).

Experimental pulmonary hypertension was induced in rats by a single subcutaneous administration of monocrotaline (60 mg kg−1). Injected animals developed characteristic features of pulmonary hypertension including medial hypertrophy of pulmonary arteries and right ventricular hypertrophy.

Reverse transcriptase–polymerase chain reaction (RT–PCR), immunohistochemistry and Western immunoblot analysis indicated that histopathological alterations were associated with upregulation of the ClC‐3 mRNA and protein expression in both smooth muscle cells of hypertensive pulmonary arteries and in cardiac myocytes.

RT–PCR analysis of mRNA, extracted from canine cultured PASMCs, indicated that incubation with the inflammatory mediators endothelin‐1 (ET‐1), platelet‐derived growth factor (PDGF), interleukin‐1beta (IL‐1β) and tumor necrosis factor alpha (TNFα), but not transforming growth factor beta (TGFβ), upregulated ClC‐3 mRNA.

Adenovirus‐mediated delivery and overexpression of ClC‐3 in canine PASMCs improved cell viability against increasing concentrations of hydrogen peroxide (H2O2, range 50–250 μM).

In conclusion, upregulation of ClC‐3 in rat hypertensive lung and heart is a novel observation. Our functional data suggest that upregulation of ClC‐3 is an adaptive response of inflamed pulmonary artery, which enhances the viability of PASMCs against reactive oxygen species.

British Journal of Pharmacology (2005) 145, 5–14. doi:10.1038/sj.bjp.0706135
The role of joint nerves and mast cells in the alteration of vasoactive intestinal peptide (VIP) sensitivity during inflammation progression in rats
Authors: McDougall Jason J , Barin Ali Kursat
Published: February 2005

The present study examined the peripheral effects of vasoactive intestinal peptide (VIP) on rat knee joint blood flow during acute and chronic inflammation. The involvement of joint nerves and synovial mast cells on these effects was also investigated.

Prior to blood flow assessment, animals were deeply anaesthetised with ethyl carbamate (urethane; 2 mg kg−1 i.p.). Local application of VIP (10−13–10−9 mol) onto the capsular surface of normal rat knee joints caused a dose‐dependent increase in synovial perfusion with an ED50 of 1.2 × 10−11 mol. The dilator effect of the peptide was transient with the maximal response occurring approximately 1 min after drug administration.

VIP‐induced vasodilatation was blocked by co‐administration of the VIP receptor antagonist VIP6–28 (10−9 mol). The inhibitory effect of the antagonist was consistent across the entire VIP dose range (P=0.01).

The vasoresponsiveness to VIP was significantly attenuated in acutely inflamed joints; however, surgical denervation of acutely inflamed knees re‐established the vasodilator effect of the neuropeptide.

Topical application of VIP to 1‐ and 3‐week adjuvant monoarthritic knees produced a hyperaemic response, which was not significantly different from normal (P=0.06 and 0.73 for 1‐ and 3‐week adjuvant treated joints, respectively).

Stabilisation of synovial mast cells by disodium cromoglycate (cromolyn) pretreatment did not alter the vasoresponsiveness to VIP in acute or chronically inflamed joints.

The vasodilatatory effect of VIP is lost during acute knee joint inflammation and this abrogated effect is neurally dependent. In the chronic phase of knee joint inflammation, VIP‐mediated hyperaemia recovers to normal levels. Synovial mast cells do not influence the vasomotor effects of exogenously applied VIP in inflamed knee joints.

British Journal of Pharmacology (2005) 145, 104–113. doi:10.1038/sj.bjp.0706169
Validation of IKKβ as therapeutic target in airway inflammatory disease by adenoviral‐mediated delivery of dominant‐negative IKKβ to pulmonary epithelial cells
Authors: Catley Matthew C , Chivers Joanna E , Holden Neil S , Barnes Peter J , Newton Robert
Published: February 2005

Asthma is an inflammatory disease of the lungs and the transcription factor NF‐κB regulates the production of numerous inflammatory mediators that may have a role in the pathogenesis of asthma. Hence, the signalling pathways leading to NF‐κB activation are considered prime targets for novel anti‐inflammatory therapies. The prevention of NF‐κB activity in mice, through the knockout of IKKβ or p65, causes fatal liver degeneration in utero making it difficult to determine the full implications of inhibiting NF‐κB activity in tissues physiologically relevant to human diseases.

This study used adenovirus delivery of a dominant inhibitor of NF‐κB (IκBαΔN) and dominant‐negative IKKα (IKKα(KM)) and IKKβ (IKKβ(KA)) to investigate the role of the individual IKKs in NF‐κB activation and inflammatory gene transcription by human pulmonary A549 cells.

Overexpression of IKKβ(KA) or IκBαΔN prevented NF‐κB‐dependent transcription and DNA binding. IKKβ(KA) also prevented IκBα kinase activity. Similarly, IKKβ(KA) and IκBαΔN overexpression also inhibited IL‐1β‐ and TNFα‐dependent increases in ICAM‐1, IL‐8 and GM‐CSF in addition to IL‐1β‐mediated increases in cyclooxygenase‐2 expression, whereas IKKα(KM) overexpression had little effect on these outputs.

IKKβ(KA) also reduced cell viability and induced caspase‐3 and PARP cleavage regardless of the stimuli, indicating the induction of apoptosis. This effect seemed to be directly related to IKKβ kinase activity since IκBαΔN only induced PARP cleavage in TNFα‐treated cells.

These results demonstrate that inhibition of IKKβ and NF‐κB suppresses inflammatory mediator production and reduces A549 cell viability. Thus, novel therapies that target IKKβ could have potent anti‐inflammatory effects and may be beneficial in the treatment of certain cancers.

British Journal of Pharmacology (2005) 145, 114–122. doi:10.1038/sj.bjp.0706170
Seasonality of calving in pasture-based dairy systems: its effects on herbage production, utilisation and dry matter intake
Authors: García S. C. , Holmes C. W.
Published: February 2005

The objectives of the present work were to evaluate the influence of season of calving on (i) pasture productivity, (ii) total dry matter intake by cows, and (iii) the relationship between intake and milk yield of individual cows. Three systems in which the cows calved either in autumn, in spring or half in autumn, half in spring, were managed according to a set of common guidelines during 3 consecutive years. Herbage accumulation rate (HAR) was estimated by the difference between 2 successive grazings (pre- and post-grazing herbage mass). Average HAR in each month was similar between systems. However, small differences in HAR were observed between calving systems in spring and summer, and appeared to be related to the proportion of the farmlet closed for silage. Herbage dry matter intakes varied seasonally (P<0.05), but independently of the calving system (P>0.05). Cows from different calving systems, offered 8.9 or 2.5 kg maize silage dry matter per cow daily in the paddocks, consumed an average of 6.0 and 1.4 kg, respectively. A large variation in intake was observed between individual cows with ranges from 2 to 10 kg and 0.2 to 2.9 kg, respectively. In conclusion, applying the same grazing management decisions to systems with contrasting calving dates resulted in only small seasonal, but not annual, differences in pasture HAR. The results also indicated that when maize silage is fed in the paddock, wastage can be high and variation in intake between individual cows can also be large.
Interspecific hybridisation and cytogenetic studies in ornamental sunflower breeding
Authors: Atlagic J. , Secerov-Fiser V. , Marinkovic R.
Published: February 2005

This study examined the possibility of using wild sunflower species as a source of desirable genes in breeding the common ornamental sunflower. Crossing 7 wild species with 6 inbred lines of common ornamental sunflower produced F1 hybrid plants only with Helianthus argophyllus and H. petiolaris. The F1’s exhibited the dominant phenotype of the wild species. Cytological analysis showed irregularities in meiosis and low pollen fertility in F1 hybrids. The most frequent configuration was 15 bivalents and 1 quadrivalent and 13 bivalents and 2 quadrivalents. The presence of quadrivalents at diakinesis indicated the occurrence of translocations. In a small percentage of anaphase I meiocytes, chromosome bridges were detected resulting from inversions. The occurrence of translocations and inversions showed the differences in chromosome structure among the crossed species. Helianthus argophyllus and H. petiolaris may be useful in ornamental sunflower breeding as valuable sources of desirable genes.
Bioactivity of Fusarium oxysporum f. sp. glycines and Sclerotium rolfsii filtrates on egg hatching, survival and infectivity of juveniles of Meloidogyne incognita race 2
Authors: Adekunle O. K. , Akinsanmi O. A.
Published: February 2005

The effects of culture filtrates of Fusarium oxysporum and Sclerotium rolfsii on egg hatching and juvenile survival of Meloidogyne incognita in vitro and impact of these filtrates on infectivity of M. incognita were investigated on soybean seedlings. Five- and 10-day-old filtrates of F. oxysporum caused 65 and 54% egg-hatching inhibition, while that of S. rolfsii caused 61 and 49% inhibition, respectively. Juveniles of M. incognita died within 6 days when incubated in 5-day-old filtrate of F. oxysporum, while the similar filtrate of S. rolfsii caused 100% juvenile mortality on the fifth day. Filtrates reduced root galling, egg population, number of adult females in soybean plants at harvest and also soil population. Culture filtrates could be used as source of biological nematicides.
Comparative productivity of irrigated short-term ryegrass (Lolium multiflorum) pasture receiving nitrogen, grown alone or in a mixture with white (Trifolium repens) and Persian (T. resupinatum) clovers
Authors: Lowe K. F. , Fulkerson W. J. , Walker R. G. , Armour J. D. , Bowdler T. M. , Slack K. , Knight R. I. , Moody P. W. , Pepper P. M.
Published: February 2005

Dairy farms in subtropical Australia use irrigated, annually sown short-term ryegrass (Lolium multiflorum) or mixtures of short-term ryegrass and white (Trifolium repens) and Persian (shaftal) (T. resupinatum) clover during the winter–spring period in all-year-round milk production systems. A series of small plot cutting experiments was conducted in 3 dairying regions (tropical upland, north Queensland, and subtropical southeast Queensland and northern New South Wales) to determine the most effective rate and frequency of application of nitrogen (N) fertiliser. The experiments were not grazed, nor was harvested material returned to the plots, after sampling.
Rates up to 100 kg N/ha.month (as urea or calcium ammonium nitrate) and up to 200 kg N/ha every 2 months (as urea) were applied to pure stands of ryegrass in 1991. In 1993 and 1994, urea, at rates up to 150 kg N/ha.month and to 200 kg N/ha every 2 months, was applied to pure stands of ryegrass; urea, at rates up to 50 kg N/ha.month, was also applied to ryegrass–clover mixtures.
The results indicate that applications of 50–85 kg N/ha.month can be recommended for short-term ryegrass pastures throughout the subtropics and tropical uplands of eastern Australia, irrespective of soil type. At this rate, dry matter yields will reach about 90% of their potential, forage nitrogen concentration will be increased, there is minimal risk to stock from nitrate poisoning and there will be no substantial increase in soil N. The rate of N for ryegrass–clover pastures is slightly higher than for pure ryegrass but, at these rates, the clover component will be suppressed. However, increased ryegrass yields and higher forage nitrogen concentrations will compensate for the reduced clover component. At application rates up to 100 kg N/ha.month, build-up of NO3–-N and NH4+-N in soil was generally restricted to the surface layers (0–20 cm) of the soil, but there was a substantial increase throughout the soil profile at 150 kg N/ha.month. The build-up of NO3–-N and NH4+-N was greater and was found at lower rates on the lighter soil compared with heavy clays. Generally, most of the soil N was in the NO3–-N form and most was in the top 20 cm.
Persistence of Phalaris aquatica in grazed pastures. 1. Plant and tiller population characteristics
Authors: Cullen B. R. , Chapman D. F. , Quigley P. E.
Published: February 2005

Phalaris tiller and plant population characteristics were monitored in sown Australian phalaris–subterranean clover pastures over 3 seasons (1999–2001) to determine the impact of fertiliser and grazing method on phalaris persistence in south-western Victoria. Four grazing systems were tested: set-stocked, low phosphorus (P) fertiliser input (SS low P); set-stocked, high P fertiliser input (SS high P); simple rotation, high P (RG 4 paddock); and intensive rotation, high P (RG intensive). Within each year there was no significant difference in tiller density (tillers/m2) between the grazing systems. Phalaris tiller density declined (P<0.05) on all treatments from June 1999 to June 2001. There was a significant effect of grazing method on tiller size (mg/tiller); tillers growing under rotational grazing systems were much larger than those in set-stocked systems. There was some evidence of tiller size density compensation across the grazing management treatments; however, the slope of the trade-off between tiller size and density was not as steep as those reported for other species. In general, the phalaris tiller populations under rotationally grazed treatments were characterised by lower density per m2 of phalaris clump and larger size, compared with the set-stocked treatments. Both the phalaris tiller and clump density declined at a similar rate on all treatments during this experiment, suggesting that there was some limitation to phalaris persistence irrespective of grazing system. Measured leaf appearance intervals (days/leaf) indicated that a lack of tillering sites was not a contributing factor in the observed tiller density decline. It is likely that the combination of high grazing pressure, below average rainfall and subsoil acidity contributed to the observed phalaris population decline.
Persistence of Phalaris aquatica in grazed pastures. 2. Regenerative bud and tiller development
Authors: Cullen B. R. , Chapman D. F. , Quigley P. E.
Published: February 2005

The summer survival, regeneration and tillering characteristics of phalaris (Phalaris aquatica cv. Australian) were examined in pastures using 4 grazing management systems in a grazing trial in south-western Victoria over 2 consecutive seasons. The grazing treatments tested covered a range of management intensities from a set-stocked with low phosphate input system to an intensive rotation with high phosphate. The soil fertility and grazing methods tested had no effect on the plant developmental characteristics measured in the field. The phalaris tiller population regenerated exclusively from dormant buds, as no vegetative tillers formed in the late spring/early summer survived through to the autumn break. On average, 3.7 regenerative buds were formed on each reproductive tiller. Half of these regenerative buds grew out in the field during the following growing season forming a new tiller. Of the new tillers formed, 71% produced at least 1 secondary tiller, with the average total number of secondary and higher tillers produced per new tiller being 4.5. Across both seasons, an average of 6.7% of the maximum vegetative tiller density became reproductive, and these reproductive tillers each contributed 3.7 buds to the population’s regenerative capacity in the following season. A simple model of bud development and tiller turnover showed that each regenerative bud at the start of the growing season was replaced by 0.54 buds at the start of the following season, indicating a substantial population decline. Reproductive tiller density was identified as a key limitation to phalaris persistence in this experiment. It is proposed that lowering grazing intensity during spring will increase the proportion of tillers that become reproductive and enhance phalaris persistence.
Row configuration as a tool for managing rain-fed cotton systems: review and simulation analysis
Authors: Bange M. P. , Carberry P. S. , Marshall J. , Milroy S. P.
Published: February 2005

Rain-fed cotton production can be a significant proportion (average 17%) of the Australian Cotton Industry. One of the management techniques that rain-fed cotton growers have is to modify row configuration. Configurations that have entire rows missing from the sowing configuration are often referred to as ‘skip row’. Skip configurations are used to: increase the amount of soil water available for the crop, which can influence the potential lint yield; reduce the level of variability or risk associated with production; enhance fibre quality; and reduce input costs. Choosing the correct row configuration for a particular environment involves many, often complex, considerations. This paper presents an examination of how rain-fed cotton production in Australia is influenced by row configuration with different management and environmental factors. Data collated from field experiments and the cotton crop simulation model OZCOT, were used to explore the impact of agronomic decisions on potential lint yield and fibre quality and consequent economic benefit. Some key findings were: (i) soil water available at sowing did not increase the advantage of skip row relative to solid configurations; (ii) reduced row spacing (75 cm) did not alter lint yield significantly in skip row crops; (iii) skip row, rain-fed crops show reasonable plasticity in terms of optimum plant spacing within the row (simular to irrigated cotton); (iv) sowing time of rain-fed crops would appear to differ between solid and skip row arrangements; (v) skip row configurations markedly reduce the risk of price discounts due to short fibre or low micronaire and this should be carefully considered in the choice of row configuration; and (vi) skip configurations can also provide some savings in variable costs. In situations where rain-fed cotton sown in solid row configurations is subject to water stress that may affect lint yield or fibre quality, skip row configurations would be a preferential alternative to reduce risk of financial loss.
Elevated erythrocyte phosphoribosylpyrophosphate and ATP concentrations in Japanese sumo wrestlers
Authors: Nishida Y. , Akaoka I. , Hayashi E. , Miyamoto T.
Published: February 2005

1. Japanese sumo wrestlers have a diet rich in energy, which results in marked obesity. Their plasma urate and triglyceride levels were significantly elevated.

2. Erythrocyte phosphoribosylpyrophosphate (PRPP) and ATP concentrations in sumo wrestlers were significantly elevated when compared to the levels in control subjects.

3. There were no significant differences in erythrocyte PRPP synthetase (EC2.7.6.1), purine nucleoside phosphorylase (EC2.4.2.1) and hypoxanthine guanine phosphoribosyl transferase (EC2.4.2.8) activities between sumo wrestlers and control subjects.

4. Erythrocyte adenosine kinase (EC2.7.1.20), adenosine deaminase (EC3.5.4.4) and adenine phosphoribosyl transferase (EC2.4.2.7) activities in sumo wrestlers were significantly elevated.

5. It seems that sumo wrestlers have an increased turnover of adenine nucleotides which may contribute to hyperuricaemia.
Excess energy intake promotes the development of hypoalbuminaemia in rats fed on low-protein diets
Authors: Lunn P. G. , Austin S.
Published: February 2005

1. A group of rats were givenad lib.a diet with a protein-energy: total energy (P:E) value of 0·03. Other animals received the same protein intake (g/kg body-weight per d) as this group, but had their energy consumption reduced to either 90, 80. 70, 60 or 50% of thead lib.value.

2. The restricted growth rate of rats fed on the P:E – 0·03 dietad lib.has been shown to be due entirely to their insufficient protein consumption. In contrast, energy intake was far in excess of that required for maintenance and the limited amount of growth.

3. Carcass analysis demonstrated that some of the excess energy intake was stored as fat, but a greater part had been dissipated, presumably by diet-induced thermogenesis.

4. The plasma concentration of triiodothyronine (T3) was elevated in all animals consuming excess energy and was significantly related to both the total surplus and the amount of energy dissipated.

5. In the group of animals restricted to 50% of thead lib.intake, energy rather than protein appeared to be the factor limiting growth. Energy intake was below estimated requirements for maintenance and was associated with values for plasma T3that were lower than those found in well-fed control rats.

6. Although all the animals had similar protein intakes, plasma albumin concentration differed between the groups and was found to be inversely proportional to the energy intake. Thus it was lowest in animals receiving foodad lib.and rose to near normal values in the most-severely-restricted rats.

7. It is suggested that hypoalbuminaemia, and perhaps other features of protein deficiency, seen in animals fed on low-P:E diets may occur as an undesirable consequence of the metabolic response required to deal with excess energy consumption.
Dietary-induced obesity: effect of dietary fats on adipose tissue cellularity in mice
Authors: Bourgeois Francine , Alexiu Andre , Lemonnter Daniel
Published: February 2005

1. Male and female mice, 4 weeks old, were fedad lib.diets containing various amounts of lard (0–300 g/kg) or various kinds of dietary fats (300 g/kg) for 13 weeks. Fat cell number and size were determined by a histological method in three different adipose sites.

2. Lard at 200 g/kg diet (43% energy from lipids) was sufficient to promote fat cell hyperplasia in the parametrial fat. Hyperplasia was also observed in the subcutaneous fat in males. The relationship between fat cell hypertrophy and the level of lard in the diet was dependent on site and sex.

3. Obesity was produced whatever the kind of dietary fat eaten: lard, beef tallow, sunflower oil or soya-bean oil. In the subcutaneous depot of males given lard, fat cell size and number were increased, but only cell hypertrophy was observed in those given soya-bean oil. In the female groups of mice fat cell hyperplasia or hypertrophy or both were related to the adipose site but not the kind of dietary fat.

4. It is concluded that dietary fats of different origin can induce obesity in mice. The effects on adipose tissue cellularity depend on the levels and kind of fat eaten, the adipose site and sex.
Effect of pharmacological doses of ascorbic acid on the hepatic microsomal haemoproteins in the guinea-pig
Authors: Sutton Judith L. , Basu T. K. , Dickerson J. W. T.
Published: February 2005

1. Ascorbic acid deficiency results in a reduction in the activity of the hepatic mixed function oxidase systems in the guinea-pig. In this study, male Dunkin-Hartley guinea-pigs were given 0, 50, 100, 200 or 300 mg ascorbic acid/d in two equal doses in buffered sucrose solution (200 g/l) for 4 d. Controls received an equal volume of sucrose solution.

2. A dose of 50 mg ascorbic acid/d resulted in a significant rise in the specific activities of both cytochromes P-450 and b5. At doses of 200 and 300 mg ascorbic acid/d the concentration of both haemoproteins was significantly lower than the control values. These effects were mirrored by total microsomal haem concentration.

3. These results suggest that when given in large doses, ascorbic acid ceases to act simply as a vitamin and should be considered a drug competing for substrates and cofactors with co-administered drugs and endogenous substrates such as cholesterol.
Artificial rearing of pigs
Authors: Newport M. J. , Keal H. D.
Published: February 2005

1. Pigs weaned at 2 d of age were given diets in which a functional fish-protein concentrate (FFPC) supplied 0 (diet U), 350 (diet H), 525 (diet I) or 700 (diet G) g crude protein (nitrogen × 6·25, CP)/kg total CP. The remainder of the CP was supplied by dried skim-milk and whey. The diets were reconstituted (200 g dry matter (DM)/l), from two spray-dried powders (diets U and G) and these were mixed in the proportions 1:1 and 1:3 (v/v) to give diets H and I respectively. All four diets were given at hourly intervals on a scale based on live weight, and supplemented with vitamins and minerals. All diets contained the same amounts of calcium, phosphorus, sodium and potassium.

2. In an experiment to 28 d of age with ten pigs/diet, performance was inversely related to the amount of FFPC in the diet. One pig (diet I) and four pigs (diet G) died after scouring. In healthy pigs, N retention (g/d per kg live weight) was not affected by partial replacement of dried skim-milk (diet H).

3. Digestion of protein was studied in a further experiment with eight pigs/diet, killed at 7 d of age and at 1 h after a feed. The amount, pH, DM and total N contents of the digesta in the stomach were also inversely related to the amount of FFPC in the diet.

4. FFPC had no consistent effect on proteolytic enzymes. Greater amounts of trypsin and chymotrypsin were present in the distal compared with the proximal region of the small intestine, but source of dietary protein had no effect.

5. The proportion of non-protein-N in the total N in digesta from the small intestine was lower in pigs receiving FFPC suggesting that this protein may be more resistant to proteolysis than milk proteins. The apparent absence of an increase in enzyme secretion when FFPC was given could, therefore, explain the decrease in performance.

6. Some general effects of non-milk proteins from this series of experiments in the baby pig are discussed. It is suggested that performance may be inversely related to the rate of gastric emptying, as indicated by the amount of DM in the stomach. Unlike milk, other sources of protein did not coagulate in the stomach, and reduced the pH, DM and total N contents of the digesta. Giving diets containing a single-cell protein did appear to stimulate proteolytic enzyme secretion, unlike fish or soya-bean proteins.
Iron status of suckling rats as influenced by maternal diet during gestation and lactation
Authors: Kochanowski Barbara A. , Sherman Adria R.
Published: February 2005

1. Two experiments are reported. In Expt 1, pregnant Sprague–Dawley rats (200–220 g) were given purified diets containing 35, 75, 150 or 300 mg Fe/kg throughout gestation and lactation. In Expt 2, the levels of Fe given were 250 and 300 mg/kg diet.

2. Litters were standardized at birth to contain seven pups. On day 20 of lactation blood, milk, spleen and liver were collected for Fe analysis.

3. A dietary Fe concentration of 35 mg/kg maintained maximum weight gain, food intake, liver and spleen weight, haemoglobin concentration and packed cell volume in the growing maternal rat through 20 d of lactation. Dam liver and spleen Fe concentrations were maximized between 75 and 250 mg Fe/kg diet.

4. Pups (20-d-old) nursed by dams given 35 mg Fe/kg tended to have lower body and organ weights compared to other groups. Liver and spleen Fe concentrations increased with increasing maternal dietary Fe and were significantly increased between 150 and 250 mg Fe/kg.
Dietary protein and the growth of rats infected with the tapeworm Hymenolepis diminuta
Authors: Hall Andrew
Published: February 2005

1. Weanling rats fed on a relatively low protein diet were infected with several intestinal tapeworms. The weight gain and daily food intake of the rats were measured for 3 weeks before the animals were killed and the adult tapeworms recovered. The tissues of the rats and worms were then analysed for protein. Controls were provided by uninfected rats either pair fed or fed ad lib. For comparison, a similar experiment was conducted on rats fed on a relatively high protein diet.

2. The effect of the infection on the protein-malnourished rats and of the low level of protein on the worms were apparently not significant. The amount of protein contained in the worm burdens was less than 1·5% of the average total intake of the protein-malnourished rats.
The origin of urinary aromatic compounds excreted by ruminants
Authors: Martin A. K. , Milne J. A. , Moberly P.
Published: February 2005

1. Studies were made of the extent to which p-cresol, catechol, quinol and orcinol infused through rumen or abomasal cannulas to sheep were recovered in their urine.

2. Rumen fermentation of dietary phenolic compounds caused the excretion of simple phenols in the urine. In decreasing order of magnitude these were: p-cresol, catechol, phenol and 4-methylcatechol with only traces of quinol and orcinol.

3. The percentages of rumen-infused p-cresol or orcinol recovered as increments in the urinary phenol outputs of sheep (94 and 99% respectively) following infusion showed that rumen degradation of these phenols was negligible.

4. After rumen infusion of catechol and quinol, mean recoveries of these phenols in urine were only 55 and 77% respectively. Possible reasons for these incomplete recoveries are discussed.

5. Studies were also made of the use of the urinary phenol output of phenols characteristic of particular forages as indices of their voluntary intake by sheep. Calluna vulgaris L. (Hull) (heather) may contain 1300–3600 mg/kg dry matter (DM) of orcinol and 200–800 mg/kg DM of quinol as β-glycosides. When heather was offered ad lib. to sheep given one of five levels of grass, linear relationships were found between heather intake and urinary quinol and orcinol outputs.

6. The urinary output of aromatic acids was also determined when sheep ate grass and heather. Urinary phenylacetic acid output was linearly related to grass but not to heather intake. The relationship between urinary phenylacetic acid output and grass intake could vary with different forages but that between orcinol output and heather intake was considered a useful index of heather intake.

7. Methods for the assay of urine phenols are discussed.