BIOLOGY AND INDUSTRY IN COOPERATION     

Krogh A 《Science (New York, N.Y.)》1938,88(2288):416-419

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Computing inbreeding coefficients and the inverse numerator relationship matrix in large populations of honey bees          下载免费PDF全文

Richard Bernstein  Manuel Plate  Andreas Hoppe  Kaspar Bienefeld 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2018,135(4):323-332

The inbreeding coefficients are considered in breeding decisions, and the inverse numerator relationship matrix A ^?1 is a prerequisite for breeding value estimation. Polyandry and haploid males are among the specifics of relationships between honey bees. Brascamp and Bijma (2014) averaged out the manifold possible relationships among honey bees that appear to have the same parents in a pedigree and assigned a single entry in A to animals that behave as a unit, for example, the workers of a hive. Their methods of calculation connected full‐sibs in the variance matrix of the Mendelian sampling terms D , via nonzero off‐diagonal elements. This impedes the inversion of A and the closely connected calculation of inbreeding coefficients, because efficient algorithms for this task take D to be a diagonal matrix. Memory limitations necessitate their use for large data sets. We adapted the quickest of them to the block diagonal matrix D , that is postulated for the honey bee. To our knowledge, the presented algorithm is the first one that facilitates the method of Brascamp and Bijma (2014) on large data sets.  相似文献   

Indigestion in Young Calves: I. Different Lactose Levels in Milk Diets and Milk Replacers     

P. Slagsvold  B. Laksesvela  K. Flatlandsmo  N. Krogh  T. L. Ulstein  N. Ek  T. Landsverk 《Acta veterinaria Scandinavica》1977,18(2):194

Increasing the lactose content of different milk replacers or milk diets by approx. 30 % of the dry matter increased the frequency of diarrhoea the first 10–12 days in young calves on all occasions in 5 experiments comprising 120 calves. For all diets taken together, this effect was highly significant. Total daily intakes of lactose amounted to 200–480 g. When lactose was given on top of the milk rations, the growth rate increased significantly, whereas the growth rate was usually insignificantly reduced when lactose replaced other nutrients in milk diets or milk replacers, their levels of protein and fat becoming low. Albumin and total protein in blood plasma were significantly lower when the dietary protein level was low. Milk replacers with 20 or 40 % whey powder, replacing skim milk powder, performed equally well, but gave significantly less growth than the old-fashioned feeding of whole milk-skim milk. Intake of hay and barley and a number of clinical and histological or pathological parameters did not vary consistently with dietary level of whey powder or lactose. Feeding whole milk all the time resulted in low intake of hay and barley and poorly developed forestomachs, but high dressing-out %. Substituting soya for part of the skim milk powder in milk replacers gave abomasal content with no curds. In most cases, pH in the rumen appeared to be nearly up to neutral until the calves ate ground barley, about 1 month old.  相似文献   

Intoxication in cattle caused by a batch of sugar beet pulp (author's transl)]     

K Nielsen  P Krogh  T Moller 《Nordisk veterinaermedicin》1975,27(9):401-410

During the period from Dec. 7th 1972 to Jan. 8th 1973 76 cattle deaths were reported in 20 herds on the island of M?on and the adjacent south-eastern area of Sealand. The disease was characterized by a sudden onset and a rapid and invariably fatal course. Initially, there was a loss of appetite, depression, excessive salivation and incoordination. These symptoms progressed to paralysis and, in some animals, trmor and convulsions. Death usually ensued less than 2 hours after the first observation of symptoms. Losses in the herds varied from 1 to 12 animals. In herds with multiple incidents the majority of deaths occurred in the 24-hour-period following observation of the first case. Pathology: Gross lesions were few and inconclusive. Histology revealed marked dilatation of cerebral and maningeal blood vessels (arterioles, venoles and capillaries), with perivascular edema and haemorrhage. Adjacent neurons and glia cells showed various degrees of degeneration, apparently secondary to the vascular lesion. In all affected herds sugar beet pulp from one particular sugar mill had been used during the period preceding the outbreak. The syndrome was reproduced by feeding sugar beet pulp from this batch to two heifers. The heifers showed symptoms after 19 and 32 days' feeding, resp. and died after a few hours. Clinical and pathological features were identical with those observed in the spontaneous disease. Thus, it was proved that the particular batch of pulp was responsible for the disease. The investigation did not, however, reveal a toxic factor in this batch. Analyses for lead, arsenic, mercury, nitrite, alkyl phosphates, chlorinated insecticides and Cl. botulinum toxin were negative. Batches of the sugar beet pulp showed pronounced microbial deterioration, the flora being dominated by yeasts and filamentous fungi (moulds). Several species of fungi have been isolated but so fat their possible role in the etiology of the syndrome remains unsettled. The syndrome bears some resemblance to cerebrocortical necrosis (C.C.N.) but differs in several clinical and pathological details. It is tentatively suggested that the beet pulp may have contained one or more toxic substances that interfere with microbial activity in the rumen, resulting in a disturbance of synthesis or absorption of essential metabolites. The clinical, epidemiological and pathological findings are compatible with the hypothesis that the syndrome might be due to fungal toxins. Accordingly, the isolated fungi are now being studied in more detail.  相似文献   

Bovine cryptosporidiosis in Denmark. 2. Cryptosporidia associated with neonatal calf diarrhea     

H V Krogh  S A Henriksen 《Nordisk veterinaermedicin》1985,37(1):42-47

In recent years cryptosporidia have often been identified in diarrheic calves of under one month old, either as the sole pathogenic agent or in combination with other diarrhea-causing infectious agents. In 203 cases of bovine cryptosporidiosis, recorded over a period of two years, cryptosporidia were present in such great numbers that they would seem to be of causal significance. The calves were from three days to five weeks old. In 111 cases (55%) a monoinfection with cryptosporidia occurred, while in the rest of the cases mixed infections with other agents associated with calf diarrhea were demonstrated, especially rotavirus (61 cases) and coronavirus (32 cases); in addition, mixed infections with ETEC (four cases), septicaemic E. coli (two cases), salmonellosis (11 cases), and BVD and coccidiosis (one case each) were seen. In 87 (10%) of 849 4-21-day-old dead calves a massive occurrence of cryptosporidia was demonstrated. Extreme emaciation was noted in 36 of 122 autopsied calves. Most of these calves were more than 14 days old, and mono-infection with cryptosporidia was demonstrated in two thirds of them. In younger calves, more acute cases of cryptosporidiosis were commoner, often in connection with concomitant infections with rota- or coronavirus.  相似文献   

Acute idiopathic polyneuritis with spontaneous remission in an Abyssinian cat     

Aurélien Jeandel  Kaspar Matiasek  Stéphane Blot 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(12):1279-1282

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Increased understanding of the cereal phytase complement for better mineral bio-availability and resource management     

Henrik Brinch-Pedersen  Claus Krogh MadsenInger Bæksted Holme  Giuseppe Dionisio 《Journal of Cereal Science》2014

The present paper summarizes the current state of knowledge on cereal phytase that are particular relevant for improving mineral and phosphate bio-availability. Phytases can initiate the hydrolysis of phytate, the main storage form of phosphate in cereals and the major anti-nutritional factor for the bio-availability of micronutrients in human nutrition. The composition and levels of mature grain phytase activity (MGPA) in cereals is of central importance for efficient phytate hydrolysis. The MGPA varies considerably between species. Substantial activity is present in Triticeae tribe cereals like wheat, barley and rye whereas non-Triticeae cereals such as maize and rice have very little MGPA. Recent studies have determined the evolutionary relationships of phytases in Triticeae and non-Triticeae and highlighted the importance of the purple acid phosphatase phytases (PAPhys). In the Triticeae, PAPhys are synthesized during grain development (PAPhy_a) and during germination (PAPhy_b). In non-Triticeae species, only PAPhys that are mainly synthesized during germination were identified. The new knowledge provides new opportunities for modulating the MGPA in Triticeae cereals but also indicates that nutritionally relevant levels of MGPA are unlikely to be achieved in non-Triticeae by conventional breeding. Increasing MGPA in barley via cisgenesis is discussed.  相似文献   

Bovine mycotic abortion in Denmark     

H V Krogh 《Nordisk veterinaermedicin》1985,37(1):27-33

A survey is given of the occurrence of mycotic infections associated with abortion in Danish cattle. During a period of six years a total of 748 samples of placenta material were examined. Mycotic abortion was demonstrated in 101 cases (14%). The case rate was significantly higher (21%) during the winter months from December through February than during the rest of the year (10%). Abortions occurred as from the 135th day of pregnancy, with maximum in the eighth month, where 45% of all cases were observed. A. fumigatus was demonstrated in 77 cases, Mucor spp. in 11 cases, Absidia spp. in 5 cases, and a mixed infection with A. fumigatus and Mucor spp. in 3 cases. In 5 cases the fungi were demonstrated by microscopic and histological examination, but not by culture. The annual occurrence of mycotic abortion varied from 10% to 24% of cases of abortion examined. The latter figure was recorded in a year following a particularly heavy rainfall in the month of June.  相似文献   

Microbial and microfaunal community structure in cropping systems with genetically modified plants   总被引：3，自引：3，他引：3  

Bryan S. Griffiths  Sandra Caul  Jacqueline Thompson  A. Nicholas E. Birch  Jrme Cortet  Mathias N. Andersen  Paul Henning Krogh 《Pedobiologia》2007,51(3):195-ECOGEN

Soils from field sites at Foulum (DK), Narbons (FR) and Varois (FR) planted with genetically modified maize expressing either the insecticidal Bacillus thuringiensis protein (Bt) or herbicide tolerance (HT), as described elsewhere in this volume, were analysed for nematodes, protozoa and microbial community structure. These analyses were mirrored in single-species testing and in mesocosm experiments, and were coordinated with field samples taken for microarthropods, enchytraeids and earthworms so allowing for cross-comparison and a better understanding of the results observed in the field. Over the first 2 years of the field experiments (in 2002 and 2003), the effect of Bt-maize was within the normal variation expected in these agricultural systems. Sampling in 2004 and 2005 was expanded to include the effects of tillage (i.e. reduced tillage versus conventional tillage) and also the use of HT-maize. Tillage had major effects regardless of soil type (Varois or Foulum), with reduced-tillage plots having a greater abundance of microfauna and a different microbial community structure (measured both by phospholipid fatty-acid analysis (PLFA) and by community-level physiological profiling (CLPP)) from conventionally tilled plots. Grass, as a contrasting cropping system to maize, also had an effect regardless of soil type and resulted in greater microfaunal abundance and an altered microbial community structure. Differences in crop management, which for the Bt-maize was removal of the insecticide used to control European corn borer and for HT-maize was a change in herbicide formulation, were only tested at single sites. There were differences in microbial community structure (CLPP but not PLFA) and sporadic increases in protozoan abundance under the Bt-crop management. The HT-maize cropping system, which covered a shorter period and only one site, showed little change from the conventional system other than an altered microbial community structure (as measured by PLFA only) at the final harvest. The Bt-trait had a minimal impact, with fewer amoebae at Foulum in May 2003, fewer nematodes at Foulum in May 2004 but more protozoa at Varois in October 2002 and an altered microbial community structure (PLFA) at Foulum in August 2005. These were not persistent effects and could not be distinguished from varietal effects. Based on the field evaluations of microfauna and microorganisms, we conclude that there were no soil ecological consequences for these communities associated with the use of Bt- or HT-maize in place of conventional varieties. Other land management options, such as tillage, crop type and pest management regime, had significantly larger effects on the biology of the soil than the type of maize grown.  相似文献   

Ultrafast bond softening in bismuth: mapping a solid's interatomic potential with X-rays     

Fritz DM  Reis DA  Adams B  Akre RA  Arthur J  Blome C  Bucksbaum PH  Cavalieri AL  Engemann S  Fahy S  Falcone RW  Fuoss PH  Gaffney KJ  George MJ  Hajdu J  Hertlein MP  Hillyard PB  Horn-von Hoegen M  Kammler M  Kaspar J  Kienberger R  Krejcik P  Lee SH  Lindenberg AM  McFarland B  Meyer D  Montagne T  Murray ED  Nelson AJ  Nicoul M  Pahl R  Rudati J  Schlarb H  Siddons DP  Sokolowski-Tinten K  Tschentscher T  von der Linde D  Hastings JB 《Science (New York, N.Y.)》2007,315(5812):633-636

Intense femtosecond laser excitation can produce transient states of matter that would otherwise be inaccessible to laboratory investigation. At high excitation densities, the interatomic forces that bind solids and determine many of their properties can be substantially altered. Here, we present the detailed mapping of the carrier density-dependent interatomic potential of bismuth approaching a solid-solid phase transition. Our experiments combine stroboscopic techniques that use a high-brightness linear electron accelerator-based x-ray source with pulse-by-pulse timing reconstruction for femtosecond resolution, allowing quantitative characterization of the interatomic potential energy surface of the highly excited solid.  相似文献