Fungicidal activity of 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinones and related compounds     

Niels Jacobsen  Anita Wengel 《Pest management science》1986,17(6):686-690

The fungicidal activity of a series of 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinones and their acetates has been assessed against various fungi in vitro and against others, notably powdery mildews, in vivo, and the activity compared with that of analogous compounds bearing saturated side chains. Several of the compounds demonstrated a broad spectrum of activity in vitro. Whereas the presence of α-unsaturation in the side chain is essential for the in-vitro activity against the non-obligate fungi tested, it is of virtually no importance for the curative effect against Erysiphe graminis on barley. Only the corresponding acetates had activity against the latter pathogen.  相似文献   

Absorption-spectrophotometric determination of DNA (deoxyribonucleic acid) in milk ad modum Feulgen. Accuracy of analysis, specificity, correlation to content of cells     

P S Madsen 《Acta veterinaria Scandinavica》1969,10(4):319-344

The Feulgen reaction is examined by absorption photometric measurements at 565 nm with correction for varying background absorption at 485 nm. This correction is done to improve the accuracy of measuring.Examinations of the accuracy of analysis for the Feulgen reaction and the direct microscopic cell counts show that the former is of the same order, when the cell count is made at a working factor of 17,000.The standard deviations expressed in percentage of the reaction value are greater the lower the reaction is, whereas the absolute standard deviation is reduced.It has been demonstrated that addition of a few (< 5) µg of DNA per ml milk can give Feulgen reaction. The coefficient of correlation between log added amount of DNA and log Feulgen reaction is 0.98.The coefficient of correlation between log Feulgen reaction and log cell content depends on the accuracy at which both determinations are made. In a determination of cell content at a working factor of 550, and several determinations of the Feulgen reaction the coefficient of correlation (r) is found to be 0.98. A cell content determination at a working factor of 20,000 and a single determination of Feulgen reaction on each milk sample yields r = 0.83.An examination of foremilk samples of the same cell content reveals on an average the highest reaction in mastitis-affected quarters which have been infected within the last 4 weeks. Quarters that have been infected for more than 4 weeks, on an average show the second highest reaction, whereas quarters of physiological cell number show the lowest reaction.The DNA-content in most cases is found to be too high compared with the number of cells counted microscopically. The DNA-content in centrifugated cells corresponds to the one calculated theoretically. The surplus DNA-content can be demonstrated in the cell-free skim milk fraction, probably originating from destroyed cells.The studies performed suggest that determination of the content of 2-deoxyribose in milk by means of the Feulgen reaction is a more correct measure of the cell content in the milk than is the microscopic cell count. Studies are being continued for illustration of these conditions.  相似文献   

Puberal estrus and ovulation and subsequent estrous cycle patterns in the ewe     

W C Foote  N Sefidbakht  M A Madsen 《Journal of animal science》1970,30(1):86-90

  相似文献   

Homing of Gyrodactylus salaris and G. derjavini (Monogenea) on different hosts and response post-attachment     

Buchmann K  Madsen KK  Dalgaard MB 《Folia parasitologica》2004,51(2-3):263-267

In natural European waters, the congeneric monogeneans Gyrodactylus derjavini Mikailov, 1975 and G. salaris Malmberg, 1957 are primarily found on brown trout Salmo trutta L. and Atlantic salmon Salmo salar L., respectively. Interestingly, rainbow trout, Oncorhynchus mykiss (Walbaum), originating from North America, is as susceptible as brown trout to G. derjavini. However, the mechanisms involved in this host specificity are poorly understood but may include behavioural, mechanical and chemical factors affecting parasite attraction, attachment, feeding, reproduction and host responses. In the present laboratory work, this question has been studied. Detached parasites (either G. derjavini or G. salaris) were offered a choice in small aquaria between fry of rainbow trout, Atlantic salmon and carp Cyprinus carpio L. Within 48 hours more than 90% of G. derjavini colonised rainbow trout and left salmon almost uninfected. Some parasites were found on carp. During the same time span, more than 60% of G. salaris attached to salmon, the rest infected rainbow trout and none were found on carp. Following attachment, the parasites need appropriate stimuli to initiate feeding and reproduction but even such a successful specific colonisation can be followed by a host response. Both humoral and cellular elements have been suggested to participate in these reactions but in the present work it was demonstrated by immunoblotting and immunocytochemistry that no antibodies in host mucus and host plasma bound to any parasite structures or epitopes.  相似文献   

A phenetic analysis of morphological variation in Citrullus lanatus in Namibia     

Gillian L. Maggs-Kölling  Sten Madsen  Jørgen L. Christiansen 《Genetic Resources and Crop Evolution》2000,47(4):385-393

Morphological data recorded from field trials using Citrullus lanatus germplasm collected in Namibia were used to analyse and compare the various morphotypes of this species. The experiment comprised wild types and local landraces as well as commercial cultivars. Cluster analysis supported the indigenous classification system used in Namibia, in which Citrullus types are distinguished based on gross morphology, ecology and usage and grouped into seed, cooking and fresh-eating (watermelon) types. Commercial watermelon cultivars formed a distinct cluster. Wide variation was found within the local types whereas the genetic basis of the commercial type appears to be narrow. The commercial cultivars were most closely related to local watermelon types and more distantly related to the wild types, whereas the cooking melons form an intermediate group.  相似文献   

Effects of management practices on yield and quality of milk from smallholder dairy units in urban and peri-urban Morogoro,Tanzania     

Kejeri A. Gillah  George C. Kifaro  Jorgen Madsen 《Tropical animal health and production》2014,46(7):1177-1183

A longitudinal study design was used to assess the management, chemical composition of cows’ milk and quantify the microbial load of raw milk produced at farm level. Data were collected between December 2010 and September 2011 in Morogoro municipality. Milk samples were collected once every month and analysed for butter fat (BF), crude protein (CP), total solids (TS) and solids non-fat (SNF). Total bacterial count (TBC) and coliform counts (CC) were normalized by log transformation. The average milk yield was 7.0 l/day and was not influenced by feeding systems and breeds. Dairy cows owned by people who had no regular income produced more milk than government employees and retired officers. Means of BF, TS, SNF and CP were similar in different feeding systems. Wet season had significantly higher TBC (5.9 log₁₀ cfu/ml) and CC (2.4 log₁₀ cfu/ml) but feeding systems had no effect. Stocking density influenced TBC but not CC. It can be concluded that dairy cows produced low milk yield and its quality was poor.  相似文献   

Relationship between cobalamin‐dependent metabolites and both serum albumin and alpha1‐proteinase inhibitor concentrations in hypocobalaminemic dogs of 7 different breeds     

Niels Grützner  Jan S. Suchodolski  Jörg M. Steiner 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2014,43(4):561-566

  相似文献   

Genetic connections between dressage and show-jumping horses in Dutch Warmblood horses     

G. Rovere  P. Madsen  E. Norberg  J. A. M. van Arendonk  B. J. Ducro 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2014,64(1):57-66

Abstract

During the last decades, the breeding practice within the Dutch Warmblood studbook (KWPN) has resulted in an increasing specialisation of horses into show-jumping (JH) and dressage (DH). The objective of this study was to describe the effect of the specialisation on the connectedness between the subpopulations of JH and DH horses registered by KWPN. The subpopulations comprised 23,800 JH horses and 18,125 DH horses, born between 1995 and 2009. Genetic similarity (GS), genetic pool in common (GC_x) based on the marginal genetic contribution of common ancestors and coefficient of relationship (r) between and within subpopulations were analysed in three periods of time to describe changes in genetic connectedness between subpopulations. A decline in GS (0.97–0.45), GC_0.5 (0.69–0.13) and r (0.018–0.014) in the recent years was observed. Both subpopulations have a common genetic pool; however, if the specialisation process continues, it will result in two unrelated (genetic) groups.  相似文献   

Climate-driven bedrock incision in an active mountain belt   总被引：2，自引：0，他引：2  

Hartshorn K  Hovius N  Dade WB  Slingerland RL 《Science (New York, N.Y.)》2002,297(5589):2036-2038

Measurements of fluvial bedrock incision were made with submillimeter precision in the East Central Range of Taiwan, where long-term exhumation rates and precipitation-driven river discharge are independently known. They indicate that valley lowering is driven by relatively frequent flows of moderate intensity, abrasion by suspended sediment is an important fluvial wear process, and channel bed geometry and the presence of widely spaced planes of weakness in the rock mass influence erosion rate and style.  相似文献   

Mantophasmatodea: a new insect order with extant members in the Afrotropics     

Klass KD  Zompro O  Kristensen NP  Adis J 《Science (New York, N.Y.)》2002,296(5572):1456-1459

A new insect order, Mantophasmatodea, is described on the basis of museum specimens of a new genus with two species: Mantophasma zephyra gen. et sp. nov. (one female from Namibia) and M. subsolana sp. nov. (one male from Tanzania). This is the first time since 1914 that a newly described extant insect taxon has proved unplaceable within a recognized order. Mantophasmatodeans are apterous carnivores. Their closest phylogenetic relationships may be to Grylloblattodea (ice-crawlers) and/or Phasmatodea (stick insects), but the morphological evidence is ambiguous. Raptophasma Zompro from Baltic amber is assigned to the Mantophasmatodea, revealing a wider previous range for the lineage.  相似文献