Experiments on the longevity,fecundity and migration of Anoplodiscus cirrusspiralis (Monogenea) on the marine fish Pagrus auratus (Bloch & Schneider) (Sparidae)     

West  Roubal 《Journal of fish diseases》1998,21(4):299-303

  相似文献   

辽西温室甜瓜一年一大茬栽培优质高产施肥技术     

付秀会 《蔬菜》2023,(2):25-27

针对喀左县日光温室甜瓜一年一大茬栽培所面临的土壤障碍明显、产量不高、品质下降、病虫危害加重等实际问题,通过改变传统施肥方法,使上述问题得到了一定缓解。在合理应用有机肥基础上,根据温室土壤养分状况和甜瓜需肥规律,开展了肥料应用种类、比例、数量、最佳施肥时期和方法研究,探索出一套适合喀左地区日光温室甜瓜一年一大茬栽培的高产高效施肥技术,从甜瓜不同生长发育时期出发,总结出适量应用育苗肥、施足基肥、根据不同生长发育时期追肥、做好叶面喷肥、适量应用微肥等合理施肥方法,使温室甜瓜每667 m²产量较农民习惯施肥增加905.61 kg,效益增加5 433.66元。  相似文献   

Lack of evidence of conserved lentiviral sequences in pigs with post weaning multisystemic wasting syndrome.          下载免费PDF全文

A Bratanich  M Lairmore  W Heneine  C Konoby  J Harding  K West  G Vasquez  G Allan    J Ellis 《Canadian journal of veterinary research》1999,63(3):207-211

  相似文献   

A 0.5-million-year record of millennial-scale climate variability in the north atlantic   总被引：8，自引：0，他引：8  

JF McManus  DW Oppo  JL Cullen 《Science (New York, N.Y.)》1999,283(5404):971-975

Long, continuous, marine sediment records from the subpolar North Atlantic document the glacial modulation of regional climate instability throughout the past 0.5 million years. Whenever ice sheet size surpasses a critical threshold indicated by the benthic oxygen isotope (delta18O) value of 3.5 per mil during each of the past five glaciation cycles, indicators of iceberg discharge and sea-surface temperature display dramatically larger amplitudes of millennial-scale variability than when ice sheets are small. Sea-surface temperature oscillations of 1 degrees to 2 degreesC increase in size to approximately 4 degrees to 6 degreesC, and catastrophic iceberg discharges begin alternating repeatedly with brief quiescent intervals. The glacial growth associated with this amplification threshold represents a relatively small departure from the modern ice sheet configuration and sea level. Instability characterizes nearly all observed climate states, with the exception of a limited range of baseline conditions that includes the current Holocene interglacial.  相似文献   

Myocarditis and abortion associated with intrauterine infection of sows with porcine circovirus 2.   总被引：24，自引：0，他引：24  

K H West  J M Bystrom  C Wojnarowicz  N Shantz  M Jacobson  G M Allan  D M Haines  E G Clark  S Krakowka  F McNeilly  C Konoby  K Martin  J A Ellis 《Journal of veterinary diagnostic investigation》1999,11(6):530-532

Porcine circovirus 2 (PCV2) is a recently identified agent that has been associated with postweaning multisystemic wasting syndrome (PMWS) in swine populations. In this report, the potential spectrum of disease associated with PCV2 is expanded by evidence of vertical transmission and associated reproductive failure. PCV2 was isolated from a litter of aborted piglets from a farm experiencing late-term abortions and stillbirths. Severe, diffuse myocarditis was present in 1 piglet associated with extensive immunohistochemical staining for PCV2 antigen. Variable amounts of PCV2 antigen were also present in liver, lung, and kidney of multiple fetuses. The presence of other agents that have been associated with fetal lesions and abortion in swine, including porcine parvovirus, porcine reproductive respiratory syndrome virus, encephalomyocarditis virus, and enterovirus, could not be established.  相似文献   

Synergistic effects of concurrent challenge with bovine respiratory syncytial virus and 3-methylindole in calves.     

H R Bingham  P S Morley  T E Wittum  T M Bray  K H West  R D Slemons  J A Ellis  D M Haines  M A Levy  C F Sarver  W J Saville  V S Cortese 《American journal of veterinary research》1999,60(5):563-570

OBJECTIVE: To evaluate the potential synergy between bovine respiratory syncytial virus (BRSV) and 3-methylindole (3MI) in inducing respiratory disease in cattle. ANIMALS: 20 mixed-breed beef calves. PROCEDURE: A 2 X 2 factorial design was used, with random assignment to the following 4 treatment groups: unchallenged control, BRSV challenge exposure (5 X 10(4) TCID50 by aerosolization and 5.5 X 10(5) TCID50 by intratracheal inoculation), 3MI challenge exposure (0.1 g/kg of body weight, PO), and combined BRSV-3MI challenge exposure. Clinical examinations were performed daily. Serum 3MI concentrations, WBC counts, PCV, total plasma protein, and fibrinogen concentrations were determined throughout the experiment. Surviving cattle were euthanatized 7 days after challenge exposure. Pulmonary lesions were evaluated at postmortem examination. RESULTS: Clinical respiratory disease was more acute and severe in cattle in the BRSV-3MI challenge-exposure group than in cattle in the other groups. All 5 cattle in this group and 3 of 5 cattle treated with 3MI alone died or were euthanatized prior to termination of the experiment. Mean lung displacement volume was greatest in the BRSV-3MI challenge-exposure group. Gross and histologic examination revealed that pulmonary lesions were also most severe for cattle in this group. CONCLUSIONS AND CLINICAL RELEVANCE: Feedlot cattle are commonly infected with BRSV, and 3MI is produced by microflora in the rumen of all cattle. Our results suggest that there is a synergy between BRSV and 3MI. Thus, controlling combined exposure may be important in preventing respiratory disease in feedlot cattle.  相似文献   

Phase velocities of rayleigh waves in the MELT experiment on the east pacific rise   总被引：2，自引：0，他引：2  

DW Forsyth  SC Webb  LM Dorman  Y Shen 《Science (New York, N.Y.)》1998,280(5367):1235-1238

The phase velocities of Rayleigh waves increase more rapidly with distance from the East Pacific Rise (EPR) axis than is predicted by models of conductive cooling of the lithosphere. Low velocities near the axis are probably caused by partial melt at depths of 20 to 70 kilometers in a zone several hundred kilometers wide. The lowest velocities are offset to the west of the EPR. Wave propagation is anisotropic; the fast direction is approximately perpendicular to the ridge, parallel to the spreading direction. Anisotropy increases from a minimum near the axis to 3 percent or more on the flanks.  相似文献   

Predatory dinosaur remains from madagascar: implications for the cretaceous biogeography of gondwana   总被引：1，自引：0，他引：1  

SD Sampson  LM Witmer  CA Forster  DW Krause  PM O'Connor  P Dodson  F Ravoavy 《Science (New York, N.Y.)》1998,280(5366):1048-1051

Recent discoveries of fossil vertebrates from the Late Cretaceous of Madagascar include several specimens of a large theropod dinosaur. One specimen includes a nearly complete and exquisitely preserved skull with thickened pneumatic nasals, a median frontal horn, and a dorsal projection on the parietals. The new materials are assigned to the enigmatic theropod group Abelisauridae on the basis of a number of unique features. Fossil remains attributable to abelisaurids are restricted to three Gondwanan landmasses: South America, Madagascar, and the Indian subcontinent. This distribution is consistent with a revised paleogeographic reconstruction that posits prolonged links between these landmasses (via Antarctica), perhaps until late in the Late Cretaceous.  相似文献   

The Effect of Insulin Coma on Uropepsin Excretion     

Jacobs JS  Tempereau CE  West PM 《Science (New York, N.Y.)》1952,116(3004):86-87

  相似文献   

Don't go breaking apart: Anthropogenic disturbances predict meadow fragmentation of an endangered seagrass     

Daniel S. Swadling  Greg J. West  Peter T. Gibson  Roger J. Laird  Tim M. Glasby 《水产资源保护:海洋与淡水生态系统》2023,33(1):56-69

1. Although it is well established that human activities are linked to the loss of seagrasses worldwide, the influence of anthropogenic disturbances on the habitat fragmentation of seagrass meadows is less understood. This information is essential to identify how humans are modifying seascapes and what disturbances pose the greatest risk to seagrasses, which is pertinent given the rapid urbanization occurring in coastal areas.
2. This study examined how the habitat fragmentation of an endangered seagrass Posidonia australis varied in relation to several anthropogenic disturbances (i.e. human population, marine infrastructure, terrestrial run-off and catchment land-usage) within 10 estuaries across 620 km of coastline in New South Wales, Australia.
3. When comparing between estuaries, the fragmentation of P. australis meadows was significantly greater in estuaries adjacent to highly populated metropolitan centres – generally in the Greater Sydney region. At sites within estuaries, the density of boat moorings was the most important predictor of habitat fragmentation, but there was also evidence of higher fragmentation with increased numbers of jetties and oyster aquaculture leases.
4. These results suggest that the fragmentation of seagrass meadows will become more pervasive as the human population continues to grow and estuarine development increases. Strategies to mitigate anthropogenic disturbances on seagrass meadow fragmentation could include prohibiting the construction of boat moorings and other artificial structures in areas where seagrasses are present or promoting environmentally friendly designs for marine infrastructure. This knowledge will support ongoing management actions attempting to balance coastal development and the conservation of seagrasses.

  相似文献