Long-term productivity growth and sustainability of Greek irrigated agriculture     

SM Fakhrul Islam  Mohd. Kamruzzaman 《Archives of Agronomy and Soil Science》2013,59(3):311-324

The present study examines the long-term productivity growth and sustainability of Greek irrigated agriculture. A log linear trend model was used to measure long-term productivity growth, and the total factor productivity (TFP) approach measures the sustainability of the irrigated production system. A time series database of inputs and outputs data were used for the production period of 1961?–?2001 (41 years) which revealed that there is an increasing trend in the irrigated area of the country. The annual growth rate of the irrigated area is 2.6% during this time period. The long-term trends in yields of crops grown in irrigated agriculture are positive. Fertilizer use rate per ha sharply increases during this period. The productivity of irrigated Greek agriculture also increases over the time period as a result of the introduction of High Yielding Variety (HYV), seed, fertilizer and water technology. The measurement of TFP indices indicates that the long-term trend in productivity growth of irrigated Greek agricultural system is positive. The result implies that the irrigated Greek agricultural production system has long-term sustainability. The result also indicates that fertilizer, fixed capital, rainfall and temperature are positively contributing to the mean production of Greek irrigated agriculture. On the other hand, pesticide, labour and fixed capital reduces variability of irrigated agriculture. To this end, long-term agricultural sustainability depends on patterns of input use.  相似文献   

Live and inactivated vaccine regimens against caecal Salmonella Typhimurium colonisation in laying hens          下载免费PDF全文

PJ Groves  SM Sharpe  WI Muir  A Pavic  JM Cox 《Australian veterinary journal》2016,94(10):387-393

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Negative pressure wound therapy using a portable single‐use device for free skin grafts on the distal extremity in seven dogs          下载免费PDF全文

AJ Miller  RG Cashmore  AM Marchevsky  M Havlicek  PM Brown  SM Fearnside 《Australian veterinary journal》2016,94(9):309-316

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Effects of pimobendan on myocardial perfusion and pulmonary transit time in dogs with myxomatous mitral valve disease: a pilot study          下载免费PDF全文

SM Apple  G Menciotti  L Braz‐Ruivo  S Crosara  J Häggström  M Borgarelli 《Australian veterinary journal》2016,94(9):324-328

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Third‐compartment cannulation in alpacas using a polyurethane gastrostomy tube     

GW Smith  MP Gerard  NB Campbell  DM Foster  SM Smith  JL Davis 《Australian veterinary journal》2009,87(12):487-491

Objective To develop a simple and effective surgical technique for third‐compartment cannulation in alpacas. Design Prospective study using six adult male alpacas. Methods General anaesthesia was induced and a polyurethane gastrostomy tube was surgically implanted into the distal portion of the third compartment. Results Three of the alpacas retained their cannulas for a 100‐day period; however, three cannulas were dislodged during the study. Two of the three dislodged cannulas were replaced during a second surgical procedure. Cannulas were well tolerated by the alpacas and all animals remained clinically healthy during the study period. Third compartment contents did not leak from the cannulation site. The tubes were manually removed following the completion of the study and the small defect in the body wall quickly healed over in all animals. Conclusion Surgical placement of polyurethane tubes designed for percutaneous endoscopic gastrostomy is a useful method of cannulating the third compartment in camelids. This technique can be used for experimental studies and possibly could be used for nutritional support and fluid therapy in sick camelids that might need long‐term care.  相似文献   

Molecular mechanism of Chinese medicine formula (Bushen Bugu Tang) for the treatment of postmenopausal osteoporosis     

TENG Xiao-ying  WANG Lian-tang  Huang L  Kumta SM 《园艺学报》2004,20(11):2005-2010

AIM: To study the molecular mechanism of Chinese medicine formula Bushen Bugu Tang (BSBGT) for the treatment of postmenopausal osteoporosis (PMO). METHODS: Forty female SD rats were divided into four groups: the sham group, OVX group, estrogen treatment group and BSBGT treatment group, ten for each, difference operation and treatment were given. Subsequently, bone mineral density (BMD), bone histomorphometric changes and collagen type I expression in the femur of these rats were examined. In order to position the target of the formula acting on bone, the effect of BSBGT on regulation of mRNA levels of RANKL and OPG, two key factors for regulating osteoclastogenesis, by using rat calvarial-derived stromal cell cultrues, was elucidated. RESULTS: The BSBGT formula was found as effective as estrogen in preventing the reduction of BMD, the trabecular area and trabecular numbers in femora and also the decrease in collagen type I expression following ovariectomy. RT-PCR resulted showed that both estrogen and BSBGT significantly up-regulated OPG mRNA level and down-regulated RANKL mRNA level, resulting in an increased ratio of OPG/RANKL in cultured rat stromal cells. CONCLUSIONS: The ratio of OPG/RANKL within the osseous environment determines whether bone formation predominates bone resorption. We therefore concluded that the BSBGT formula might be as effective as estrogen in prevention of postmenopausal osteoporosis through the mechanism of up-regulating RANKL expression and down-regulating OPG expression in osteoblast/stromal cells.  相似文献   

The Current State of Solar Modeling     

J Christensen-Dalsgaard  W Dappen  SV Ajukov  ER Anderson  HM Antia  S Basu  VA Baturin  G Berthomieu  B Chaboyer  SM Chitre  AN Cox  P Demarque  J Donatowicz  WA Dziembowski  M Gabriel  DO Gough  DB Guenther  JA Guzik  JW Harvey  F Hill  G Houdek  CA Iglesias  AG Kosovichev  JW Leibacher  P Morel  CR Proffitt  J Provost  J Reiter  EJ Rhodes  FJ Rogers  IW Roxburgh  MJ Thompson  RK Ulrich 《Science (New York, N.Y.)》1996,272(5266):1286-1292

Data from the Global Oscillation Network Group (GONG) project and other helioseismic experiments provide a test for models of stellar interiors and for the thermodynamic and radiative properties, on which the models depend, of matter under the extreme conditions found in the sun. Current models are in agreement with the helioseismic inferences, which suggests, for example, that the disagreement between the predicted and observed fluxes of neutrinos from the sun is not caused by errors in the models. However, the GONG data reveal subtle errors in the models, such as an excess in sound speed just beneath the convection zone. These discrepancies indicate effects that have so far not been correctly accounted for; for example, it is plausible that the sound-speed differences reflect weak mixing in stellar interiors, of potential importance to the overall evolution of stars and ultimately to estimates of the age of the galaxy based on stellar evolution calculations.  相似文献   

Capacitation of Frozen Thawed Buffalo Bull (Bubalus bubalis) Spermatozoa with Higher Heparin Concentrations     

A Mehmood  M Anwar  SM Saqlan Naqvi 《Reproduction in domestic animals》2007,42(4):376-379

The present study was conducted to examine the effect of high heparin concentration on capacitation of buffalo spermatozoa with a short incubation time. Frozen thawed spermatozoa from three buffalo bulls were pooled and treated with either 50, 100 or 200 microg/ml heparin for 30 min. Capacitation was evaluated by acrosome reaction of spermatozoa and in vitro fertilization rate (per cent cleavage rate, per cent cleavage index). Acrosome reaction was induced in heparin treated spermatozoa with calcium ionophore A23187 and staining was carried out with Coomassie G-250 to evaluate the response as compared with control (0 heparin + calcium ionophore). Significantly higher percentage of acrosome reaction (AR) spermatozoa was noted after heparin treatment (36.8-48.2%) as compared with control (8.1% ; p < 0.05) but differences among the three heparin concentrations were non-significant. However, a significantly higher in vitro fertilization rate was recorded in spermatozoa capacitated by 50 and 100 microg/ml heparin (80.4 and 75.9% cleavage rate, respectively) as compared with 200 microg/ml heparin (47.2% cleavage rate; p < 0.001). It is concluded that buffalo spermatozoa capacitated with 50-100 microg/ml heparin had significantly higher ability to improve in vitro fertilization rate in buffalo.  相似文献   

Energetic particles at venus: galileo results     

Williams DJ  McEntire RW  Krimigis SM  Roelof EC  Jaskulek S  Tossman B  Wilken B  Stüdemann W  Armstrong TP  Fritz TA  Lanzerotti LJ  Roederer JG 《Science (New York, N.Y.)》1991,253(5027):1525-1528

At Venus the Energetic Particles Detector (EPD) on the Galileo spacecraft measured the differential energy spectra and angular distributions of ions >22 kiloelectron volts (keV) and electrons > 15 keV in energy. The only time particles were observed by EPD was in a series of episodic events [0546 to 0638 universal time (UT)] near closest approach (0559:03 UT). Angular distributions were highly anisotropic, ordered by the magnetic field, and showed ions arriving from the hemisphere containing Venus and its bow shock. The spectra showed a power law form with intensities observed into the 120- to 280-keV range. Comparisons with model bow shock calculations show that these energetic ions are associated with the venusian foreshock-bow shock region. Shock-drift acceleration in the venusian bow shock seems the most likely process responsible for the observed ions.  相似文献   

Mercury's magnetosphere after MESSENGER's first flyby     

Slavin JA  Acuña MH  Anderson BJ  Baker DN  Benna M  Gloeckler G  Gold RE  Ho GC  Killen RM  Korth H  Krimigis SM  McNutt RL  Nittler LR  Raines JM  Schriver D  Solomon SC  Starr RD  Trávnícek P  Zurbuchen TH 《Science (New York, N.Y.)》2008,321(5885):85-89

Observations by MESSENGER show that Mercury's magnetosphere is immersed in a comet-like cloud of planetary ions. The most abundant, Na+, is broadly distributed but exhibits flux maxima in the magnetosheath, where the local plasma flow speed is high, and near the spacecraft's closest approach, where atmospheric density should peak. The magnetic field showed reconnection signatures in the form of flux transfer events, azimuthal rotations consistent with Kelvin-Helmholtz waves along the magnetopause, and extensive ultralow-frequency wave activity. Two outbound current sheet boundaries were observed, across which the magnetic field decreased in a manner suggestive of a double magnetopause. The separation of these current layers, comparable to the gyro-radius of a Na+ pickup ion entering the magnetosphere after being accelerated in the magnetosheath, may indicate a planetary ion boundary layer.  相似文献