Survey of the prevalence of warble fly larvae in market cattle in Great Britain     

A R Peters  D R Melrose 《The Veterinary record》1985,117(11):261-262

A survey of warble-infested 'fat' cattle in 57 selected livestock markets in Great Britain was carried out during June 1972 and during May each year from 1973 to 1984. The annual total number of cattle inspected varied from 41,587 to 60,481. The level of infestation increased from 22.3 per cent in 1972 to 38.0 per cent in 1976 and then declined slightly to 34.3 per cent in 1978. Following the introduction of legislation and the warble fly eradication campaign in 1978 there was a rapid decrease to 8.6 per cent infestation by 1979 and by 1984 the level was less than 0.02 per cent.  相似文献   

Development and validation of the maximal electro-shock seizure model in dogs     

Territo PR  Freise KJ  Newhall K  Barnhart SD  Peters SC  Engleking DR  Burnett TJ  Abdul-Karim B  Shannon HE 《Journal of veterinary pharmacology and therapeutics》2007,30(6):508-515

The development and validation of the maximal electro-shock (MES) model using phenobarbital (Pb) as the positive control is described. This approach builds on previous work in rodent model systems, and has been adapted to dogs as a tool for pharmaceutical dose selection. Dogs, like rodents, exhibit generalized convulsions which manifest as progressive clinical signs in a dose (electrical current) dependent fashion. At the limit (300 mA, 200 msec) animals underwent clonic-tonic convulsions consistent with complete generalized (Grand Mal) seizures with a grade 3 clinical score (CS) and a menace response time of 98.5 +/- 24.4 sec (n = 8). Pretreatment of animals with Pb at 3, 10, and 30 mg/kg, in a 4-by-4 complete block crossover design (Latin-Square), resulted in a dose-dependant reduction in CS and menace response time. Estimates of plasma Pb concentration taken prior to MES induction showed a similar dose-dependent reduction in CS and menace response time with concentration. Using a cumulative logistic regression model, a predicted 50% probability of a CS = 1 was approximately 11.4 mg/kg. In addition, plasma Pb concentrations predicted a 50% probability of a CS = 1 occurs at plasma Pb concentration of approximately 16.0 mug/mL. Combined these data suggest that MES is a useful model for evaluating generalized convulsions in canines and may provide a tool for dose selection of novel pharmaceutical compounds.  相似文献   

The long and winding road leading to the successful introgression of downy mildew resistance into onion     

O. E. Scholten  A. W. van Heusden  L. I. Khrustaleva  K. Burger-Meijer  R. A. Mank  R. G. C. Antonise  J. L. Harrewijn  W. Van haecke  E. H. Oost  R. J. Peters  C. Kik 《Euphytica》2007,156(3):345-353

Downy mildew resistance originating from Allium roylei Stearn provides a complete resistance to onions and is based on one, dominant gene. Since A. roylei can successfully be hybridized with onion (A. cepa L.), a breeding scheme aimed at the introgression of this gene was initiated ca. 20 years ago. Several setbacks in this programme were encountered, firstly the identified molecular marker linked to the downy mildew resistance locus became increasingly difficult to use and finally lost its discriminating power and secondly the final step, making homozygous introgression lines (ILs), turned out to be more difficult then was hoped. GISH analysis showed that the chromosomal region harbouring the resistance locus was the only remaining piece of A. roylei in the nuclear background of onion and it also confirmed that this region was located on the distal end of chromosome 3. It was hypothesized that some factor present in the remaining A. roylei region was lethal when homozygously present in an onion genetic background. The identification of an individual with a smaller and more distally located introgression fragment and homozygous ILs in its progeny validated this hypothesis. With the help of these nearly isogenic lines four AFLP^® markers closely linked to the resistance gene were identified, which can be used for marker-aided selection. The introduction of downy mildew resistance caused by Peronospora destructor into onion is a significant step forward in the development of environmentally-friendly onion cultivars.  相似文献   

Erhebungsuntersuchung zur Nährstoffversorgung von Picea omorika im Zusammenhang mit dem Omorikensterben     

D. Alt  R. Zimmer  M. Stock  I. Peters  I. Krupp 《植物养料与土壤学杂志》1982,145(2):117-127

A survey investigation of the relationship between nutritional factors and the decline of Picea omorika growth Soil and needle samples were collected from 193 sites of Picea omorika (mostly in private gardens) in Northern Germany ranging from normal to seriously damaged plants. The needles were analysed for N, P, K, Ca, Mg, Cu, Zn, Mn, Fe, B, Cl and Na. In the soil samples pH, P, K and Mg were determined.

• 1 In 54 cases (= 30,3% of the 178 sites with injured trees) the cause of the damage could not be established. In a few cases only (12 sites = 6,7%) Mg deficiency seemed to have caused the injuries. But in a large number of cases the needles showed high Cl contents, hence Cl toxicity was the most important cause (103 sites = 57,9%) of the damage.
• 2 The critical content of needles sampled in autumn is 0,27 % C1. Above this value CI-toxicity is highly probable and between 0,22 and 0,27 % CI it is possible.
• 3 High Cl-content is associated with mottled chlorosis and in many cases also with a brown discoloration beginning at the tip of the needle. The symptoms are usually stronger at the tips of branches than in central or basal parts.
• 4 Susceptibility to Cl-toxicity is similar for Picea omorika and Picea abies.
• 5 C1-toxicity may be caused by high application of deicing salt and Cl-containing fertilizers. Some of the fertilizers specially developed for the nutrition of conifers even contain too much Cl.

  相似文献   

A well-preserved Archaeopteryx specimen with theropod features     

Mayr G  Pohl B  Peters DS 《Science (New York, N.Y.)》2005,310(5753):1483-1486

A nearly complete skeleton of Archaeopteryx with excellent bone preservation shows that the osteology of the urvogel is similar to that of nonavian theropod dinosaurs. The new specimen confirms the presence of a hyperextendible second toe as in dromaeosaurs and troodontids. Archaeopteryx had a plesiomorphic tetraradiate palatine bone and no fully reversed first toe. These observations provide further evidence for the theropod ancestry of birds. In addition, the presence of a hyperextendible second toe blurs the distinction of archaeopterygids from basal deinonychosaurs (troodontids and dromaeosaurs) and challenges the monophyly of Aves.  相似文献   

Mutational analysis of the tyrosine phosphatome in colorectal cancers   总被引：1，自引：0，他引：1  

Wang Z  Shen D  Parsons DW  Bardelli A  Sager J  Szabo S  Ptak J  Silliman N  Peters BA  van der Heijden MS  Parmigiani G  Yan H  Wang TL  Riggins G  Powell SM  Willson JK  Markowitz S  Kinzler KW  Vogelstein B  Velculescu VE 《Science (New York, N.Y.)》2004,304(5674):1164-1166

Tyrosine phosphorylation, regulated by protein tyrosine phosphatases (PTPs) and kinases (PTKs), is important in signaling pathways underlying tumorigenesis. A mutational analysis of the tyrosine phosphatase gene superfamily in human cancers identified 83 somatic mutations in six PTPs (PTPRF, PTPRG, PTPRT, PTPN3, PTPN13, PTPN14), affecting 26% of colorectal cancers and a smaller fraction of lung, breast, and gastric cancers. Fifteen mutations were nonsense, frameshift, or splice-site alterations predicted to result in truncated proteins lacking phosphatase activity. Five missense mutations in the most commonly altered PTP (PTPRT) were biochemically examined and found to reduce phosphatase activity. Expression of wild-type but not a mutant PTPRT in human cancer cells inhibited cell growth. These observations suggest that the mutated tyrosine phosphatases are tumor suppressor genes, regulating cellular pathways that may be amenable to therapeutic intervention.  相似文献   

Monoclonal antibody-mediated tumor regression by induction of apoptosis   总被引：166，自引：0，他引：166  

B C Trauth  C Klas  A M Peters  S Matzku  P M?ller  W Falk  K M Debatin  P H Krammer 《Science (New York, N.Y.)》1989,245(4915):301-305

To characterize cell surface molecules involved in control of growth of malignant lymphocytes, monoclonal antibodies were raised against the human B lymphoblast cell line SKW6.4. One monoclonal antibody, anti-APO-1, reacted with a 52-kilodalton antigen (APO-1) on a set of activated human lymphocytes, on malignant human lymphocyte lines, and on some patient-derived leukemic cells. Nanogram quantities of anti-APO-1 completely blocked proliferation of cells bearing APO-1 in vitro in a manner characteristic of a process called programmed cell death or apoptosis. Cell death was preceded by changes in cell morphology and fragmentation of DNA. This process was distinct from antibody- and complement-dependent cell lysis and was mediated by the antibody alone. A single intravenous injection of anti-APO-1 into nu/nu mice carrying a xenotransplant of a human B cell tumor induced regression of this tumor within a few days. Histological thin sections of the regressing tumor showed that anti-APO-1 was able to induce apoptosis in vivo. Thus, induction of apoptosis as a consequence of a signal mediated through cell surface molecules like APO-1 may be a useful therapeutic approach in treatment of malignancy.  相似文献   

X-ray Absorption Spectroscopic Investigation of Trace Vanadium Sites in Coal     

Maylotte DH  Wong J  Peters RL  Lytle FW  Greegor RB 《Science (New York, N.Y.)》1981,214(4520):554-556

X-ray absorption spectroscopy was used to probe the chemical and structural environment of vanadium in coal. It was found that vanadium exists in at least two environments, in both of which it was coordinated to oxygens. There was no evidence of vanadium in nitrogen (porphyrin) or sulfide environments. It was also found that the vanadium environments in the raw coal did not survive unchanged in a liquefaction process. These findings have implications for coal cleaning processes and for trace element release into the liquefaction process stream.  相似文献   

A strategy for probing the function of noncoding RNAs finds a repressor of NFAT   总被引：3，自引：0，他引：3  

Willingham AT  Orth AP  Batalov S  Peters EC  Wen BG  Aza-Blanc P  Hogenesch JB  Schultz PG 《Science (New York, N.Y.)》2005,309(5740):1570-1573

  相似文献   

Mutations in dynein link motor neuron degeneration to defects in retrograde transport     

Hafezparast M  Klocke R  Ruhrberg C  Marquardt A  Ahmad-Annuar A  Bowen S  Lalli G  Witherden AS  Hummerich H  Nicholson S  Morgan PJ  Oozageer R  Priestley JV  Averill S  King VR  Ball S  Peters J  Toda T  Yamamoto A  Hiraoka Y  Augustin M  Korthaus D  Wattler S  Wabnitz P  Dickneite C  Lampel S  Boehme F  Peraus G  Popp A  Rudelius M  Schlegel J  Fuchs H  Hrabe de Angelis M  Schiavo G  Shima DT  Russ AP  Stumm G  Martin JE  Fisher EM 《Science (New York, N.Y.)》2003,300(5620):808-812

Degenerative disorders of motor neurons include a range of progressive fatal diseases such as amyotrophic lateral sclerosis (ALS), spinal-bulbar muscular atrophy (SBMA), and spinal muscular atrophy (SMA). Although the causative genetic alterations are known for some cases, the molecular basis of many SMA and SBMA-like syndromes and most ALS cases is unknown. Here we show that missense point mutations in the cytoplasmic dynein heavy chain result in progressive motor neuron degeneration in heterozygous mice, and in homozygotes this is accompanied by the formation of Lewy-like inclusion bodies, thus resembling key features of human pathology. These mutations exclusively perturb neuron-specific functions of dynein.  相似文献