Erratum     

Herman Timm  M. Yamaguchi  M. D. Clegg  J. C. Bishop  Guy W. Bishop  G. C. Upreti  B. B. Nagaich  E. F. Maas  J. P. Sweeney  V. J. Chapman  P. A. Hepner  R. M. Reeve 《American Journal of Potato Research》1968,45(1):40-40

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Glycine,nitrate, and ammonium uptake by classic and modern wheat varieties in a short-term microcosm study     

Jennifer R. Reeve  Jeffrey L. Smith  Lynne Carpenter-Boggs  John P. Reganold 《Biology and Fertility of Soils》2009,45(7):723-732

Plants take up nitrogen principally in the form of nitrate and ammonium; however, evidence is growing that they can also use organic N in the form of amino acids. Selecting varieties that better use organic N could be important in maximizing productivity in organic and low-input systems because these varieties may access a wider pool of available nutrients. We tested amino acid-N uptake by wheat (Triticum aestivum L.) seedlings over 24 h over a range of soil glycine concentrations. Wheat was grown in 5 ml pipette tips for 10 days prior to labeling with ¹⁴C-labeled glycine. In a second experiment, uptake of amino acid-N relative to nitrate and ammonium was tested in three pre-1940 wheat varieties (Arco, Idaed, and Red Fife), three modern varieties (Alpowa, Madsen, and Zak), and one perennial wheat variety (unreleased). Glycine-N was detected in all shoots (with the exception of the lowest soil concentration) and increased with increasing soil concentration. There were few differences in uptake between individual varieties tested but seedlings of modern varieties were more efficient at capturing organic N than classic varieties. Glycine-N constituted between 3.9% and 8.1% of total N uptake over 24 h and constituted a significantly greater proportion of total N in perennial wheat than annual wheat varieties. These results show that there may be sufficient varietal differences in organic N uptake in wheat to warrant selection for this trait in breeding programs targeted to improving N use efficiency.  相似文献   

采用综合技术措施快速育肥肉兔     

何远福 《畜禽业》1999,(6):68

Feeding pelteobagrus fulvidraco in cyclic-water tank with six different feeds over aperiod of sixty days.The results are shown as follows1.The frequency of occurrence of the foods on the stomach of pelteodagrus fulvidracocomplete feedI,I,Sliver carp meat＞pond-snail meat,pig meat＞mud-fish meat,complete feed II.Inthe case of the growth,similar changes arenoticed.2.After feeding,the protease and diastase activities of stomach and intestine show asignificant rising(p＜0.05).3.The oxygen consumption rate of pelteobagrus fulvidraco is144mg/h.kg,and increases by 13.8%than before trial,suffocation point is0.309mg/l(p＞0.05).  相似文献   

A METHOD FOR THE REMOVAL OF BACTERIAL CONTAMINANTS FROM SUSPENSIONS OF INFLUENZA VIRUS     

PERSONNEL OF U. S. NAVAL LABORATORY RESEARCH UNIT No. 《Science (New York, N.Y.)》1942,96(2502):543-544

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MYOELECTRICAL ROBOTIC SYSTEM FOR REHABILITATION PATIENTS WITH RESTRICTED MOVEMENT     

R. S. Machmud-Zadc Y. P. KondratenkoAZERBAIJAN INSTITUTE OF NIKOLAYEV SIIIPBUOIL  CHEMISTRY ILDING INSTITUTE 《保鲜与加工》1989,(2):17-26

This paper presents a robotic system for the rehabilitation of moving functions of the human body. It also shows that it is possible to apply the myoelectrical signal for correction of velocity of executive mechanisms movement. The myoelectrical signal contains information about muscle function and fatigue during the operation of the robotic system. The results of the simulation are described for. the robotic system which consists of two planar executive mechanisms. This robotic system is used for the training of the human hands.  相似文献   

钛对小麦幼苗光合特性的影响   总被引：4，自引：0，他引：4  

张启峰  张其德 《植物营养与肥料学报》1996,2(1):84-90

本文研究不钛对小麦幼苗光合特性的影响。经不同浓度的钛溶液浸种12小时的小麦幼苗,其叶片单位鲜重所含叶绿素和类胡萝卜素的量均比对照高。不同浓度的钛均能提高含等量叶绿素的叶绿体光能吸收能力、PSⅡ活性、PSⅡ原初光能转化效率和叶片潜在光合作用量子转化效率。此外,钛还能提高Mg2+对两个光系统(PSⅡ和PSⅠ)之间激发能分配的调节能力。5mg/L的钛在改善小麦光合功能方面,其效果最佳。由于钛能改善植物的光合功能。它在农业生产中将有良好应用前景。  相似文献   

Mediastinal lymphoma in dogs is homogeneous compared to thymic epithelial neoplasia and is more likely to envelop the cranial vena cava in CT images     

Elizabeth J. Reeve  Emma K. Mapletoft  Frederike Schiborra  Thomas W. Maddox  Christopher R. Lamb  Chris M.R. Warren‐Smith 《Veterinary radiology & ultrasound》2020,61(1):25-32

In order to identify CT signs that could be used to distinguish cranial mediastinal lymphoma and thymic epithelial neoplasia, a retrospective case‐control study was done. Associations between CT signs and diagnosis were tested using binary logistic regression and results expressed as odds ratio and 95% confidence interval. Sixty‐two dogs that had thoracic CT and confirmed diagnosis of lymphoma (n = 33) or thymic neoplasia (n = 29) were sampled. Thymic neoplasms included 24 thymomas and five thymic carcinomas. Dogs with thymic epithelial neoplasia were significantly older than dogs with lymphoma (median age 8.6 years versus 6.0 years, P = .007), but there were no significant differences in prevalence of clinical signs. Diagnosis of thymic epithelial neoplasia was associated with heterogeneous attenuation in pre‐ (odds ratio 23.3, 95% confidence interval, 4.5‐121.1) and post‐contrast (odds ratio 30.7, 95% confidence interval, 3.6‐265.0) images. Conversely, envelopment of the cranial vena cava by the mass was less likely with thymic epithelial neoplasia than lymphoma (odds ratio 0.07, 95% confidence interval, 0.007‐0.66). Greater standard deviation of Hounsfield unit values in post‐contrast images was associated with thymic epithelial neoplasia (P = .005). Based on ROC analysis, SD > 17HU of the mass in post‐contrast images had a sensitivity of 72% and specificity of 79% for thymic epithelial neoplasia. There were no significant differences in morphology, prevalence of calcification, mediastinal lymphadenopathy, cranial vena cava invasion, collateral vessels, or pleural fluid associated with these tumors. Thymic epithelial neoplasms tended to occur in older dogs and were heterogeneous in CT images, whereas mediastinal lymphoma was more homogeneous and more likely to envelop the cranial vena cava.  相似文献   

Distribution of freshwater crayfish in the British Isles,with particular reference to crayfish plague,alien introductions and water quality     

David M. Holdich  Ian D. Reeve 《水产资源保护:海洋与淡水生态系统》1991,1(2):139-158

1. The distribution of native and alien crayfish in the British Isles, based on records from 1970–1991, is figured at the 10 km square level and that for Britain is tabulated regionally. 2. Since 1981 crayfish plague has been recorded from six catchments in Britain and one in Ireland, and suspected from an additional four catchments in Britain; 56.2% of native crayfish sites in Britain occur in catchments from which plague has been confirmed. 3. Since the mid-1970s approximately 300 signal crayfish implants have been made in Britain. Only 117 “successful” implants of signals are known to the authors; 39 crayfish farmers were registered in 1986 and 68 by 1990. In 1989 declared production was approximately 7 tonnes. 4. Some mixed populations of natives and disease-free signals exist. Evidence for exclusion of natives is being monitored. 5. Signal crayfish are found in the flowing waters of seven catchments; 58.1% of native crayfish sites are located in catchments which support farmed and wild populations of signals. Some rapidly-expanding Turkish crayfish populations are known, particularly in the Thames catchment. 6. At least 87% of native crayfish records are from good quality waters. 7. Native populations from 88.6% of sites recorded in Britain since 1970 have either been eliminated, or are directly threatened, by crayfish plague infection, and/or habitat invasion by signals, and/or pollution. 8. The native crayfish was added to the list of species protected under the Wildlife and Countryside Act in 1986. 9. Recommendations to assist in the conservation of the native crayfish include a ban on future imports of alien crayfish, a reassessment of records, the setting up of “no-go” areas, the protection of isolated sites, and a restocking programme. 10. There are many restrictedt, healthy populations of native crayfish in areas which could be protected by designating them as Sites of Special Scientific Interest (SSSIs).  相似文献   

Potato composition: I. Tissue selection and its effects on solids content and amylose/amylopectin ratios     

M. L. Weaver  H. Timm  M. Nonaka  R. N. Sayre  R. M. Reeve  R. M. McCready  L. C. Whitehand 《American Journal of Potato Research》1978,55(2):73-82

Solids content and amylose/amylopectin ratios were determined in different parts of tubers of White Rose, Red La Soda, Kennebec, Russet Burbank, Norchip and Lenape at harvest, after storage at 7 C for 2 and 4 mo, and after reconditioning at 20 C for 3 wk following each storage period. In all cultivars, solids content was greatest in stem-end, lower in bud-end and lowest in core tissue. The relationships for distribution of solids among the different parts of the tubers was not changed by storage treatments in any of the cultivars. Amylose/amylopectin ratios were similar in all parts of the tuber. Both the solids content and amylose/amylopectin ratio were changed by storage, but not uniformly in all cultivars.  相似文献   

Distribution of oxidase enzymes in potato tubers relative to blackspot susceptibility II. Peroxidase and Catalase     

M. L. Weaver  E. Hautala  R. M. Reeve 《American Journal of Potato Research》1971,48(1):16-20

Peroxidase and catalase activities in selected potato tuber tissue were studied for differences and possible association with resistance or susceptibility to blackspot. Unbruised stem-end tissue had significantly greater peroxidase activity than did unbruised bud-end tissue. However, there was no significant difference between catalase activity at either end of the tuber; between blackspot susceptibility and peroxidase or catalase activity; and between blackspot susceptible or resistant tissue and the ratio of either catalase or peroxidase to phenolase activity. Bruising did not cause significant changes in either peroxidase or catalase activity or in ratios between these enzymes and phenolase that could be associated with susceptibility or resistance of tissue to blackspot. Studies associating enzymes with potato blackspot susceptibility have been concerned primarily with phenolases (5, 6, 10, 11, 13). Only recently has blackspot susceptibility been considered in connection with activity of other oxidase enzymes (12). It has been known for many years that peroxidase could oxidize many of the same phenols as the phenolases and produce a colored pigment very similar to melanin (7, 8). The study by Weaver et al. (12) was concerned with the possibility of peroxidase contributing to or subtracting from enzymatic discoloration of bruised potato tissue. The study also investigated the inhibitory or accelerating effect of H₂O₂ per se on the rate of oxidation of different phenolic substrates by potato enzymes, and how such reactions could be modified by addition of catalase or peroxidase. The theories of how peroxidase and catalase could contribute to susceptibility to blackspot were also discussed. The purpose of this study was to determine if potato peroxidase or catalase activityper se differed in various parts of the tuber, if these activities could be associated with resistance or susceptibility of the tissue to blackspot, and if certain relationships could be established to predict the response of potato tissue to bruising.  相似文献