The carbon budget of an adult <Emphasis Type="Italic">Pinus cembra</Emphasis> tree at the alpine timberline in the Central Austrian Alps     

Gerhard?WieserEmail author  Thomas?Gigele  Hans?Pausch 《European Journal of Forest Research》2005,124(1):1-8

We investigated carbon (C) uptake and respiratory losses of an adult Pinus cembra tree at the alpine timberline throughout an entire year by means of an automated, multiplexing gas exchange system. These chamber measurements were then combined with biomass data for scaling up the C budget to the tree level. Integrated over an entire year, the cumulative C gain of the tree under study was 23.5 kg of C in 2002. The daily C balance was negative for 5 months and the estimated total wintertime respiratory losses were 9% of the amount of C fixed during the growing season. The total annual C loss of the tree consumed 55% of the annual net C gain and the remaining surplus was stored in new tissues (36%) and used for fine root growth (9%). Thus, the overall C budget of P. cembra at the upper timberline is balanced fairly well, although the C sink strength in fine roots is strongly limited owing to low root zone temperatures when compared to conifers at lower elevation sites.  相似文献   

Serological survey for antibodies against bovine viral diarrhoea virus and Neospora caninum in a population of South Australian alpacas (Vicugna pacos)          下载免费PDF全文

PD Cockcroft  LE Dornin  RC Lambert  J Perry  MP Reichel 《Australian veterinary journal》2015,93(12):476-478

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Monensin controlled-release intraruminal capsule for control of bloat in pastured dairy cows   总被引：1，自引：0，他引：1  

LB LOWE  GJ BALL  VR CARRUTHERS†  RC DOBOS‡  GA LYNCH  PJ MOATE  PR POOLE†  SC VALENTINE 《Australian veterinary journal》1991,68(1):17-20

Monensin, a polyether ionophore antibiotic, is potentially an important agent for bloat relief in dairy cows grazing temperate legume-based pasture. A series of studies was undertaken to determine the effect of monensin, when delivered continuously in the rumen of lactating dairy cows by means of controlled-release capsules (monensin CRC). Such devices release approximately 300 mg/head/day for 100 d. A short-term pilot study made at Ruakura, New Zealand, tested monensin CRC in cows selected for high susceptibility to bloat and grazing lucerne (Medicago sativa) or red clover (Trifolium pratense). Treatment significantly reduced the incidence of bloat, while milk yield and protein yield were increased. There was no effect on fat yield. Following the pilot study, 6 large-scale field experiments involving a total of 368 lactating dairy cows, were made in Australia and New Zealand to confirm the effectiveness of monensin CRC for bloat control and to measure the effect of such treatment on milk production and composition. A severe bloat problem occurred in 2 experiments, mild bloat occurred in 2 others, while no visual signs of bloat were observed in the remaining 2 experiments. Bloat was significantly (P less than 0.05) reduced by monensin CRC treatment when data was pooled over the 4 experiments in which bloat occurred. Daily milk yield was increased in all experiments from a mean of 17.7 in untreated groups to 18.8 kg/head/day (P less than 0.05) in monensin CRC-treated cows. Protein percentage was not affected by treatment, while there was a decrease from 4.29 to 4.10% fat, although total fat yield was not affected.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Rotavirus excretion by village pigs in Papua New Guinea     

D. ALPERS  RC SANDERS†  DJ HAMPSON ‡ 《Australian veterinary journal》1991,68(2):65-67

Cohort studies were conducted on 29 pigs from 3 villages in the Highlands of Papua New Guinea. Animals ranged in age from 9 d to 5 m old. Three hundred and twenty nine faecal samples were collected from individual pigs followed over 3 to 6 w periods, and were examined for group A rotavirus antigen by ELISA, and rotaviral genomic RNA by polyacrylamide gel electrophoresis (PAGE). Electron microscopy was also conducted on selected samples. Group A rotavirus was detected in the faeces of 16 pigs with infected individuals coming from all villages. Non-group A rotavirus resembling group C was found in faeces from pigs from 2 villages. All of the group A rotaviruses examined had the same electrophoretype and this was distinct from that of the common type infecting humans in the area at the time of the study. None of the group A positive samples reacted with monoclonal antisera specific for human group A rotaviruses of serotypes 1, 2, 3, 4, or 8. The non-group A rotaviruses also all had identical electrophoretypes. In contrast to previous findings in intensive piggeries, rotavirus infection did not occur in all young pigs and was not limited to young animals under 2 m of age. Infected pigs varied in age from 12 days to 20 weeks of age. This pattern of infection was attributed to the non-intensive husbandry situations in the villages, with less opportunity for transmission to occur than in intensive piggeries.  相似文献   

Spironucleus muris in laboratory mice     

A. WHITEHOUSE  MP FRANCE  SE POPE  JE LLOYD  RC RATCLIFFE 《Australian veterinary journal》1993,70(5):193-193

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Morphological responses among crop species to full-season exposures to enhanced concentrations of atmospheric CO2 and O3     

C. Mulchi  B. Rudorff  E. Lee  R. Rowland  R. Pausch 《Water, air, and soil pollution》1995,85(3):1379-1386

Field studies using open-top chambers were conducted at USDA-BARC involving the growth of soybeans ('89 & '90), wheat ('91 & '92), and corn ('91), under increased concentrations of atmospheric CO₂ and O₃. Treatment responses were compared in all cases to plants grown in charcoal-filtered (CF) air (seasonal 7-h mean = 25±3 n mol O₃ mol^–1) having 350 or 500 mol CO₂ mol^–1. Elevated seasonal O₃ levels for the soybean, wheat, and corn studies averaged 72.2±4, 62.7±2, and 70.2 n mol O₃ mol^–1, respectively. Results presented were obtained for plants grown in silt loam soil under well-watered conditions. Grain yield increases in response to elevated CO₂ in the absence of O₃ stress averaged 9.0, 12.0, and 1.0% for soybean, wheat, and corn; respectively. Reductions in grain yields in response to the elevated O₃ treatments at 350 mol CO, mol^–1 averaged 20.0, 29.0 and 13.0% for soybean, wheat, and corn, respectively. Reductions in grain yields in response to elevated O₃ at 500 mol CO₂ mol^–1 averaged 20.0, 8.0, and 7.0% for soybean, wheat, and corn, respectively. Dry biomass and harvest index in wheat were significantly reduced by O₃ stress at 350 mol mol ¹ CO₂ but not at 500 u mol mol^–1 CO₂. Seed weight 1000^–1 for scybeans and wheat was significantly increased by CO₂ enrichment and decreased by O₃ stress. Seed weight 1000^–1 in corn was increased by O₃ stress suggesting that O₃ affected pollination resulting in fewer kernels per ear.Scientific Article No. A7784, Contribution No. 9105, Maryland Agric. Exp. Sta., Univ. of MD, College Park, MD 20472  相似文献   

The Breakdown of Olivine to Perovskite and Magnesiowustite     

Y Wang  I Martinez  F Guyot  RC Liebermann 《Science (New York, N.Y.)》1997,275(5299):510-513

San Carlos olivine crystals under laboratory conditions of 26 gigapascals and 973 to 1473 kelvin (conditions typical of subducted slabs at a depth of 720 kilometers) for periods of a few minutes to 19 hours transformed to the phase assemblage of perovskite and magnesiowustite in two stages: (i) the oxygen sublattice transformed into a cubic close-packed lattice, forming a metastable spinelloid, and (ii) at higher temperatures or longer run durations, this spinelloid broke down to perovskite and magnesiowustite by redistributing silicon and magnesium while maintaining the general oxygen framework. The breakdown was characterized by a blocking temperature of 1000 kelvin, below which olivine remained metastable, and by rapid kinetics once the reaction was activated.  相似文献   

Transcription Profile of Candidate Genes for the Acquisition of Competence During Oocyte Growth in Cattle     

IR Bessa  RC Nishimura  MM Franco  MAN Dode 《Reproduction in domestic animals》2013,48(5):781-789

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Micromechanical "Trampoline" magnetometers for use in large pulsed magnetic fields     

V Aksyuk  FF Balakirev  GS Boebinger  PL Gammel  RC Haddon  DJ Bishop 《Science (New York, N.Y.)》1998,280(5364):720-722

A silicon micromechanical magnetometer was constructed and successfully used in 60-tesla pulsed magnetic fields of less than 100-millisecond duration. The device is small, inexpensive to fabricate, and easy to use. It features a fast mechanical response (up to 50,000 hertz) and extremely high sensitivity yet is relatively robust against electrical and mechanical noise. Quantum oscillations in the magnetization of a 1-microgram sample of an organic superconductor, kappa-[bis(ethylenedithio)tetrathiafulvalene]2Cu(NCS)2, have been observed with this device.  相似文献   

Major compositional units of the moon: lunar prospector thermal and fast neutrons   总被引：2，自引：0，他引：2  

WC Feldman  BL Barraclough  S Maurice  RC Elphic  DJ Lawrence  DR Thomsen  AB Binder 《Science (New York, N.Y.)》1998,281(5382):1489-1493

Global maps of thermal and fast neutron fluxes from the moon suggest three end-member compositional units. A high thermal and low fast neutron flux unit correlates with the lunar highlands and is consistent with feldspathic rocks. The South Pole-Aitken basin and a strip that surrounds the nearside maria have intermediate thermal and fast neutron flux levels, consistent with more mafic rocks. There appears to be a smooth transition between the most mafic and feldspathic compositions, which correspond to low and high surface altitudes, respectively. The maria show low thermal and high fast neutron fluxes, consistent with basaltic rocks.  相似文献