Probabilistic viability calculations for cryopreserving vegetatively propagated collections in genebanks     

Gayle M. Volk  Adam D. Henk  Maria M. Jenderek  Christopher M. Richards 《Genetic Resources and Crop Evolution》2017,64(7):1613-1622

Vegetatively propagated plant collections within genebanks are vulnerable to threats when they are maintained in field or greenhouse conditions. International genebanking standards recommend that these collections be securely backed-up at either secondary locations or by using in vitro culture or cryopreservation. A series of tools and tables were developed to assist genebank managers in determining the predicted number of viable explants after cryopreservation procedures have been employed based on the number of samples processed and the viability for a range of confidence levels (0.5, 0.75, 0.90, 0.95, and 0.99). In addition, critical viabilities were estimated which represent the minimum viability required to have at least one viable explant for a given number of explants stored per cryovial or tube. The plant cryobanking literature was surveyed to summarize the sample processing practices that have been implemented within genebanks. The minimum number of explants predicted to be viable for accessions within these cryobanked collections was calculated based on the published minimum viability levels and numbers of explants processed. Implementation of the proposed tools and tables will allow genebank managers to determine if shifts in their current methods could result in more efficient back-up procedures.  相似文献   

The prececal and total intestinal nutrient digestibility and amino acid absorption of food yeasts in swine     

T Heinz  U Hennig  J Wünsche  G Henk 《Archives of Animal Nutrition》1989,39(12):1007-1019

In a difference experiment the apparent precaecal (pc) and total intestinal (tot) nutrient digestibility and amino acid (AA) absorption of 5 yeasts (n-alkane yeasts Fermosin and Paprin, molasses/molasses distillers residue yeast, two sulfite waste liquor yeasts) were studied. The two n-alkane yeasts were very highly digested pc, the difference to tot digestibility is only small in most cases. In contrast to this, the pc and tot digestibility values of molasses/molasses distillers residue yeast differed considerably more. The probable reason for this is too hot drying due to which pc digestibility, particularly of the crude protein, and pc AA absorption are considerably reduced. In the two sulfite waste liquor yeasts, sulfite waste liquor residues containing lignin impair especially the crude carbohydrate digestibility and the energetic feed value; the better processing conditions of origin A, however, reduced considerably the negative effects. The results confirm that each yeast origin has its specific particularities, which have to be taken into consideration when they are used in feeding.  相似文献   

Multiplication of Erwinia amylovora in fruit-trees. 1. A simulation study on limitations imposed by temperature and water,weather and soil     

Henk J. Schouten 《European journal of plant pathology / European Foundation for Plant Pathology》1991,97(3):171-186

Temperature and water may limit multiplication of the fire blight causing bacteriumErwinia amylovora in shoots of fruit-trees. To gain insight into these limitation under field conditions, two simulation models were designed: a short-term model for immediate effects of weather and soil water potential, and a long-term model for effects of rain and soil profiles on the limitations imposed by temperature and water on bacterial multiplication.In the Netherlands, in the month June, if the soil is moist and the weather average, water hardly limitsE. amylovora multiplication in shoots but, according to the short-term model, temperature reduces then the multiplication by about 60^. When the soil is dry and the potential transpiration rate of the trees high, water may limitE. amylovora multiplication in shoots considerably. According to the long-term model, rain has a delayed effect on multiplication. The effect of rain was simulated for three soil profiles representing three typical fruit growing areas in the Netherlands.  相似文献   

"The development in the teaching staff of the veterinary university is sometimes quick and often surprising." Interview by Marianne M. Sloet van Oldruitenborgh-Oosterbaan     

Vaarkamp H 《Tijdschrift voor diergeneeskunde》2005,130(17):526-528

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Philanthotoxins: A review of the diversity of actions on synaptic transmission     

Tom Piek  Stuart J. Dunbar  Karel S. Kits  Jan van Marle  Henk van Wilgenburg 《Pest management science》1985,16(5):488-494

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Intestinal translocation of Streptococcus suis type 2 EF+ in pigs     

Swildens B  Stockhofe-Zurwieden N  van der Meulen J  Wisselink HJ  Nielen M  Niewold TA 《Veterinary microbiology》2004,103(1-2):29-33

Sepsis with subsequent multisystem organ failure after translocation of bacteria from the gut is a serious risk associated with stress situations. We showed that intestinal bacterial translocation could be one of the pathways for pathogenic Streptococcus suis infections in the pig. In 24 piglets weighing 10-14 kg, free of the extracellular factor (EF+) producing phenotype of S. suis serotype 2, a silicon canula was placed in the proximal jejunum to enable intestinal inoculation and bypassing the upper alimentary tract. The pigs were individually housed. After stress induction in 18 pigs by means of a truck drive in individual cages for 1h, pigs were inoculated through the intestinal canula either with S. suis type 2 EF+ or with growth medium only, and put back in their original housing. The six not transported pigs were also inoculated with the same strain. To prevent oral self-infection, faeces were collected in a bag that was glued around the anus. Clinical and behavioral symptoms were recorded for 72 h post inoculation, and then the animals were sacrificed for pathological and bacteriological examination. In three animals, the inoculation strain was re-isolated from mesenterial lymph nodes and typically affected organs. No S. suis type 2 EF+ was detected by specific polymerase chain reaction (PCR) in any of the tonsil-swabs and -homogenates. We concluded that infection of the organs had taken place after bacterial translocation out of the gut and that the intestinal tract can be a porte d'entree for S. suis type 2 EF+.  相似文献   

Chicken lung lectin is a functional C-type lectin and inhibits haemagglutination by influenza A virus     

Hogenkamp A  Isohadouten N  Reemers SS  Romijn RA  Hemrika W  White MR  Tefsen B  Vervelde L  van Eijk M  Veldhuizen EJ  Haagsman HP 《Veterinary microbiology》2008,130(1-2):37-46

Many proteins of the calcium-dependent (C-type) lectin family have been shown to play an important role in innate immunity. They can bind to a broad range of carbohydrates, which enables them to interact with ligands present on the surface of micro-organisms. We previously reported the finding of a new putative chicken lectin, which was predominantly localized to the respiratory tract, and thus termed chicken lung lectin (cLL). In order to investigate the biochemical and biophysical properties of cLL, the recombinant protein was expressed, affinity purified and characterized. Recombinant cLL was expressed as four differently sized peptides, which is most likely due to post-translational modification. Crosslinking of the protein led to the formation of two high-molecular weight products, indicating that cLL forms trimeric and possibly even multimeric subunits. cLL was shown to have lectin activity, preferentially binding to alpha-mannose in a calcium-dependent manner. Furthermore, cLL was shown to inhibit the haemagglutination-activity of human isolates of influenza A virus, subtype H3N2 and H1N1. These result show that cLL is a true C-type lectin with a very distinct sugar specificity, and that this chicken lectin could play an important role in innate immunity.  相似文献   

Quantitative susceptibility of Streptococcus suis strains isolated from diseased pigs in seven European countries to antimicrobial agents licensed in veterinary medicine     

Wisselink HJ  Veldman KT  Van den Eede C  Salmon SA  Mevius DJ 《Veterinary microbiology》2006,113(1-2):73-82

The susceptibility of Streptococcus suis strains (n=384) isolated from diseased pigs in seven European countries to 10 antimicrobial agents was determined. For that purpose a microbroth dilution method was used according to CLSI recommendations. The following antimicrobial agents were tested: ceftiofur, cefquinome, enrofloxacin, florfenicol, gentamicin, penicillin, spectinomycin, tetracycline, tilmicosin and trimethoprim/sulphamethoxazole. Using breakpoints established by CLSI for veterinary pathogens, all strains were susceptible to ceftiofur, florfenicol, enrofloxacin and penicillin. MIC-90 values of these antibiotics were < or = 0.03, 0.5, 2 and < or = 0.13 microg/mL, respectively. A low degree of resistance was observed for gentamicin (1.3%), spectinomycin (3.6%) and trimethoprim/sulphamethoxazole (6.0%). MIC-90 values of these antibiotics were 8, 16 and 2 microg/mL, respectively. A high level of resistance was observed for tetracycline (75.1%). A MIC-90 value of 64 microg/mL was found for this antibiotic. Serotype-associated differences in MIC-90 values were observed for tetracycline, tilmicosin and trimethoprim/suphamethoxazole.  相似文献   

Combined enzymatic and high-pressure processing affect cell wall polysaccharides in berries     

Hilz H  Lille M  Poutanen K  Schols HA  Voragen AG 《Journal of agricultural and food chemistry》2006,54(4):1322-1328

The effect of high-pressure processing (HPP) on cell wall polysaccharides in berries was investigated. HPP decreased the degree of methyl esterification (DM), probably by activation of pectin methyl esterase (PME), and improved the extractability of pectins. When commercial enzyme mixtures were added to mashed berries, a synergistic effect was observed between treatment with commercial enzymes and HPP. Compared to treatment at atmospheric pressure, pectic polysaccharides were degraded to a larger extent when HPP was used. In contrast, hemicelluloses were hardly affected by the added enzymes when HPP was included, although they were degraded during similar treatment at atmospheric pressure. Additionally, the activity of rhamnose-releasing enzymes present in minor quantities might be enhanced after HPP, resulting in a decrease of rhamnose in the polymeric cell wall material. These results exploring the effect of HPP at representative conditions clearly point out the potential of HPP for polysaccharide modification.  相似文献   

Repellence of the red bud borer Resseliella oculiperda from grafted apple trees by impregnation of rubber budding strips with essential oils     

van Tol RW  Swarts HJ  van der Linden A  Visser JH 《Pest management science》2007,63(5):483-490

The red bud borer Resseliella oculiperda (Rübs.) is a pest insect of apple trees when rootstocks are grafted with scion buds by 'shield budding'. The female midges are attracted to the wounds of the grafted buds where they lay their eggs. The larvae feed on the cambium and destroy the buds completely or partially, leading to bad union of the buds with the rootstocks. Budding strips are used very often by growers to bind scion buds to rootstocks. These strips cannot prevent midges from reaching the damaged tissue. Chemical treatments applied to the grafts and other types of strip do not provide better protection against the pest and may cause other risks for growers. In orchard experiments in 2000 and 2001, the authors evaluated the repellent action provided by three essential oils and five compounds of plant origin against the midges by impregnating budding strips with them. The essential oils of lavender, Lavandula angustifolia (P. Mill.), and alpha-terpineol decreased the infestation of buds by more than 95 and 80% respectively. The other potential repellents tested [the essential oil of Juniperus virginiana (L.), citronellal, the essential oil of Cinnamomum camphora (L.) J. Presl, R-carvone, linalool and R-fenchone] decreased infestation by 67, 66, 51, 45, 37 and 25% respectively. The formulation and commercial development of budding strips impregnated with lavender oil is discussed.  相似文献