Studies of transplacental and perinatal infection with two clones of a single Aujeszky's disease (pseudorabies) virus isolate   总被引：1，自引：0，他引：1  

J G Iglesias  J W Harkness 《Veterinary microbiology》1988,16(3):243-254

The effect of Aujeszky's disease virus (ADV) infection in the last third of gestation was studied using two clones from an ADV isolate. Twelve sows were infected with one or other clone at 85 +/- 1 days of gestation. The dose of infection was 5 X 10(6) TCID50 per sow. The clinical and serological responses to the infection were different. One clone, Ls-1, produces a severe and acute illness. The course of the disease went from 9 to 14 days while the other clone, Ls-2, caused a mild or silent infection and for a shorter time. Transplacental infection occurred in only one sow which had been infected with Ls-2. The litter consisted of 8 mummified fetuses. Sows infected with Ls-1 produced piglets or mummified fetuses that were virus-negative. Perinatal infection was found in litters from both groups. Colostrum-deprived piglets that did not have postpartum contact with the sow, produced specific antibodies, 2 out of 6 born to sows infected with Ls-1 and 1 out of 4 born to sows infected with Ls-2. The antibody titers in colostrum-fed piglets were related to the extent of clinical response of the sows to the infection. Litters born to sows infected with Ls-1 had mean SNT titers from 1/12 to 1/112 while litters born to sows infected with Ls-2 showed titers of 1/2 or less than 2.  相似文献   

Penny ice cap cores, baffin island, canada, and the wisconsinan foxe dome connection: two states of hudson bay ice cover     

DA Fisher  RM Koerner  JC Bourgeois  G Zielinski  C Wake  CU Hammer  HB Clausen  N Gundestrup  S Johnsen  K Goto-Azuma  T Hondoh  E Blake  M Gerasimoff 《Science (New York, N.Y.)》1998,279(5351):692-695

Ice cores from Penny Ice Cap, Baffin Island, Canada, provide continuous Holocene records of oxygen isotopic composition (delta18O, proxy for temperature) and atmospheric impurities. A time scale was established with the use of altered seasonal variations, some volcanic horizons, and the age for the end of the Wisconsin ice age determined from the GRIP and GISP2 ice cores. There is pre-Holocene ice near the bed. The change in delta18O since the last glacial maximum (LGM) is at least 12.5 per mil, compared with an expected value of 7 per mil, suggesting that LGM ice originated at the much higher elevations of the then existing Foxe Dome and Foxe Ridge of the Laurentide Ice Sheet. The LGM delta18O values suggest thick ice frozen to the bed of Hudson Bay.  相似文献   

Strong regularities in world wide web surfing   总被引：5，自引：0，他引：5  

BA Huberman  PLT Pirolli  JE Pitkow  RM Lukose 《Science (New York, N.Y.)》1998,280(5360):95-97

One of the most common modes of accessing information in the World Wide Web is surfing from one document to another along hyperlinks. Several large empirical studies have revealed common patterns of surfing behavior. A model that assumes that users make a sequence of decisions to proceed to another page, continuing as long as the value of the current page exceeds some threshold, yields the probability distribution for the number of pages that a user visits within a given Web site. This model was verified by comparing its predictions with detailed measurements of surfing patterns. The model also explains the observed Zipf-like distributions in page hits observed at Web sites.  相似文献   

Annual cool-season legumes for forage production in mild winter areas     

Iglesias  & Lloveras 《Grass and Forage Science》1998,53(4):318-325

The forage potential of several annual winter legumes – crimson clover ( Trifolium incarnatum L.), faba beans ( Vicia faba L.), forage peas ( Pisum sativum L.), serradella ( Ornithopus sativus Brot.) and vetches ( Vicia sativa L. and Vicia villosa Roth.) – was evaluated over two growing seasons in the wet and mild winter areas of Galicia (north-west Spain) with a moderately acid soil, at the two normal harvesting dates in the region, April and May.
The results indicate that, in April, serradella and crimson clover (in the warmer location), can produce dry-matter (DM) yields of 4–5 t ha⁻¹, which is similar to other winter forages in the same area, with an average growing season of 212–237 d, corresponding to about 339–420 accumulated degree–days above 10°C (GDD₁₀). In May, mainly in the warmer location, fava beans, peas and vetches yielded on average 4·7–8·5 t ha⁻¹ DM, with an average growing season of 166–206 d but with only 233–278 GDD₁₀ units. Faba bean, with an average of 8·5 t ha⁻¹ DM in the May harvest, was the highest producing forage legume. The results also suggest that some cool-season legumes could fit into double-cropping systems based on summer crops, such as maize, because of their forage yields and nutritive value. However, in order to produce consistent DM yields, the date of sowing is crucial; they must either be sown much earlier than the dates in this study or the harvests must be delayed until the end of April.  相似文献   

The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor   总被引：1，自引：0，他引：1  

GM Keating  SW Bougher  RW Zurek  RH Tolson  GJ Cancro  SN Noll  JS Parker  TJ Schellenberg  RW Shane  BL Wilkerson  JR Murphy  JL Hollingsworth  RM Haberle  M Joshi  JC Pearl  BJ Conrath  MD Smith  RT Clancy  RC Blanchard  RG Wilmoth  DF Rault  TZ Martin  DT Lyons  PB Esposito  MD Johnston  al et 《Science (New York, N.Y.)》1998,279(5357):1672-1676

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.  相似文献   

The effect of temperature on the development of yolk‐sac larvae of European hake (Merluccius merluccius L.) under laboratory conditions          下载免费PDF全文

Carlos Guevara‐Fletcher  Paula Alvarez  Javier Sanchez  José Iglesias 《Aquaculture Research》2017,48(4):1392-1405

The effect of temperature (10, 13, 16, 19 and 22°C) on hatching, development and survival of yolk‐sac larvae of European hake, Merluccius merluccius, was studied. At 22°C the experiment was suspended because all eggs died a few hours after incubation. Five morphological indicators of larval development (standard length – SL, yolk‐sac volume – YSV, oil globule diameter – OD, body height – BH and body wet weight – BW) were analysed. SL, YSV, OD and BW of newly hatched larvae were biggest in size and weight at low temperatures (P < 0.05). Throughout the experiments, the rates of changes in SL, YSV and OD varied with temperature (P < 0.05). By contrast, BH and BW remained constant and did not show significant relationship with the effect of temperature (P > 0.05). The potential model showed that the SL growth rate varied from 0.05 to 0.08 mm day^?1 from 10.5 to 19.5°C respectively. However, at all temperatures two growth phases were identified: a rapid growth phase followed by a slow one. Rapid growth rate in length and depletion in yolk‐sac and oil globule occurred at high temperatures. After total YSV and OD consumption (death by starvation), larvae died between 8 and 14 days at 19.5 and 10.5°C respectively, reaching a maximum length of 4.3 mm at 10.5°C. Metabolic indices such as: lowest threshold temperature (T₀); effective larval development (); cumulative thermal units (TC) to complete larval development; the temperature coefficient on growth rate in length (Q₁₀) and the condition factor (K) were also studied.  相似文献   

Differential effect of cultivar and harvest date on nectarine colour,quality and consumer acceptance   总被引：1，自引：0，他引：1  

I. Iglesias  G. Echeverría 《Scientia Horticulturae》2009

The influence of nectarine cultivar and the harvest date on fruit colour, fruit size, fruit quality parameters, and consumer acceptance were assessed. The analyses were carried on cultivars with different fruit taste (acidity and sweetness), from 5-years-old trees at the IRTA-Experimental Station of Lleida (Spain). The six cultivars were grouped in three pairs in which each had a similar commercial harvest date. Each pair comprised by a non-acid cultivar and an acid cultivar, except the pair of ‘Big Top^®’ and ‘Mesembrine^®’, which included two non-acid cultivars. The nectarines were harvested at 8 days intervals on five harvest dates, three of which were before the commercial harvest date, one at commercial harvest and another 1 week after commercial harvest.  相似文献   

Studies on maternally derived antibodies to Aujeszky's disease virus in piglets born to naturally or experimentally infected sows     

G Iglesias  M Trujano 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1989,36(1):57-62

The concentration of maternally derived antibodies to Aujeszky's disease virus was compared in 10 litters born to infected sows. Four sows had been naturally infected and six were experimentally infected. Both IgG and IgM were present in piglet sera during the first days of life. IgM antibodies went rapidly to undetectable levels; IgG persisted much longer. The duration was dependent upon the original concentration. There was a clear relationship between the clinical disease experienced by the sow and the titre of antibodies in serum and colostrum; sows which had been naturally infected or experimentally infected with a highly virulent strain passed onto their litters a high amount of specific antibodies while sows which after experimental infection presented only mild clinical signs had very low titres of neutralizing antibodies and their litters were virtually devoid of specific antibodies at 3 weeks after birth. A return to detectable levels of IgM was noticed in some litters at around 9 weeks postcolostrum intake suggesting a development of a specific immune response.  相似文献   

Leukoencephalomalacia in horses     

RM CHRISTLEY  AP BEGG  DR HUTCHINS  DR HODGSON  WL BRYDEN 《Australian veterinary journal》1993,70(6):225-226

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Field trials of a formulation containing moxidectin and 6 in 1 vaccines for sheep     

CL SCHWARTZKOFF  RM COBB 《Australian veterinary journal》1996,74(3):225-227

Objective: To assess the efficacy and safety of a formulation containing moxidectin and 6 in 1 vaccine in sheep under field conditions.
Design: Efficacy and safety study.
Animals: Two hundred and five crossbred Merino lambs and two hundred and eight Merino ewes were used in the studies.
Procedure: A formulation was made for the simultaneous treatment of sheep with moxidectin and immunisation against clostridial diseases and caseous lymphadenitis. The efficacy against nematodes, vaccine response and safety were assessed.
Results: Effective control of nematodes and responses to antigens were achieved following subcutaneous administration. The formulation was safe to administer; occasional minor tissue reactions were evident, but no other adverse effects of treatment were observed in either pregnant ewes or lambs, using either the recommended dose, or an overdose of the formulation.
Conclusion: Administration of a formulation containing moxidectin, five clostridial antigens and caseous lymphadenitis antigen proved safe and efficacious under field conditions.  相似文献