响应面法优化姬松茸液体发酵培养基中红糖和酵母膏浓度   总被引：6，自引：0，他引：6  

范雷法  潘慧娟  Soccol CR  Pandey A 《食用菌学报》2005,12(3):27-31

运用响应面分析法优化姬松茸液体发酵培养基中红糖和酵母膏浓度.结果表明,红糖浓度为20.24g/L、酵母膏浓度为2.055g/L时,菌丝体生物量最高,达2.279g/L;红糖浓度为20.8g/L、酵母膏浓度为2.23g/L时,胞外多糖产量最高,达0.749g/L.  相似文献   

Lethal and sublethal effects of the neem insecticide formulation, ‘Margosan-O’, on the pea aphid     

John D. Stark  Theresa M. Rangus 《Pest management science》1994,41(2):155-160

The effects of ‘Margosan-O’ (MO) on the pea aphid, Acyrthosiphon pisum (Harris), were determined. MO significantly reduced population increase of A. pisum in a concentration-dependent manner. At a concentration equivalent to 100 mg litre^?1 of azadirachtin, population increase was c. 3.5 times lower than the control. In more detailed studies, MO significantly reduced the number of molts, longevity, and fecundity of A. pisum that had been reared on treated broad bean. Viciafaba L., plants. MO also reduced the longevity and fecundity of young adult A. pisum exposed to MO-treated broad bean. MO was slow-acting against A. pisum. Mortality caused by MO stabilised seven days after newborn A. pisum were exposed to treated broad bean and 10 days for adults. The seven day LC₅₀ for individuals exposed from birth was 27.50 mg azadirachtin liter^?1 while the 10 day LC₅₀ for adults was 53.32 mg liter^?1. Contrary to previous studies suggesting that neem insecticides are not contact toxicants, we found that MO applied topically to adult A. pisum caused effects similar to those found in individuals that fed upon treated plants. However, MO was slower-acting when applied topically. Mortality in adult A. pisum caused by topically applied MO stabilised 17 days after treatment with a resultant LD₅₀of 2.91 μg azadirachtin g^?1.  相似文献   

Further analysis of anti-human leukocyte mAbs with reactivity to equine leukocytes by two-colour flow cytometry and immunohistochemistry     

Flaminio MJ  Ibrahim S  Lunn DP  Stark R  Steinbach F 《Veterinary immunology and immunopathology》2007,119(1-2):92-99

We have reported on the reactivity of anti-human CD molecules with equine leukocytes by single-colour flow cytometry (this issue). The objectives of this additional study were to test for the reliability of the results obtained, and to obtain further information on the positive populations of lymphocytes. Two-colour flow cytometry and immunohistochemistry were performed, using many of the positive mAbs and a few questionable ones from the first part of the study. All mAbs analysed by two-colour flow cytometry could be confirmed to their previous designation as "positive" or "questionable". Most of the mAbs tested were effective in immunohistochemistry, supporting previous results. Examples of positive results will be presented and limitations of the study will be discussed briefly.  相似文献   

Presence and distribution of Borrelia burgdorferi sensu lato species in internal organs and skin of naturally infected symptomatic and asymptomatic dogs, as detected by polymerase chain reaction.     

K E Hovius  L A Stark  N M Bleumink-Pluym  I van de Pol  N Verbeek-de Kruif  S G Rijpkema  L M Schouls  D J Houwers 《The Veterinary quarterly》1999,21(2):54-58

Tissues from Dutch family dogs symptomatic for borreliosis according to established criteria and from infected but asymptomatic dogs were tested for Borrelia burgdorferi sensu lato DNA using a polymerase chain reaction. Subsequently, B. burgdorferi sensu stricto, B. garinii, B. afzelii, and B. valaisiana were identified by hybridization. Symptomatic dogs showed a higher prevalence of Borrelia in liver samples (9 of 15) than asymptomatic dogs (9 of 43) p = 0.0049. Overall, B. garinii was the most prevalent species and occurred together with up to three other species in on liver sample. B. burgdorferi sensu stricto however, was predominantly detected in samples of synovial membranes, skin, cerebrospinal fluid, bladder, heart, and bone marrow. Nine out of 10 symptomatic dogs with a very high antibody titre were positive for Borrelia DNA by PCR in one or more of these tissues. We conclude that dissemination in naturally infected European dogs occurs and that the two most prevalent species, B. burgdorferi sensu stricto and B. garinii, differ in their tropism.  相似文献   

仔猪腹泻病的鉴别诊断及综合防治     

孔爱云  赵新  庞传文  刘万成  解爱英  曹翠荣 《中国兽药杂志》2005,39(3):48-50

对仔猪腹泻病进行了摸索、研究和总结,根据不同日龄和不同临床表现进行鉴别诊断,同时可采取组织病理学、微生物学方法进一步确诊,并采取针对性防治措施,才能有效地控制仔猪腹泻病.  相似文献   

Composition of lipophilic compounds and carbohydrates in the accumulated plant litter and soil organic matter in boreal forests     

S. Stark  S. Hilli  S. Willför  A. I. Smeds  M. Reunanen  M. Penttinen  R. Hautajärvi 《European Journal of Soil Science》2012,63(1):65-74

Carbohydrates and lipophilic compounds constitute an important component of litter and soil organic matter in boreal forests, but are still poorly identified. We characterized needle litter and coarse tree litter (cones, seeds, bark and twigs) from coniferous trees (Pinus sylvestris L. and Picea abies Karst.), and moss litter (Pleurozium schreberi, Hylocomnium speldens), fermentation (F) and humus (H) layers in four boreal forest sites in Finland using a combination of sequential fractionation (non‐polar extractions, NPE; water‐soluble extractions, WSE; acid‐soluble fraction, AS) and detailed analyses on the soluble fractions using GC‐MS. Comparisons among the different layers of the soil organic horizon were used to assess which lipophilic compounds and carbohydrates increased in the F and H layers in proportion to their relative abundance in the litter layer and thus might have a large potential to accumulate in soil organic matter. Both concentrations and relative proportions of different compounds varied among the soil layers. Several of the fatty acids (FAs) found in the litter samples were absent in the F and the H layers. Needle and coarse tree litter contained a wide range of di‐ and triterpenes, but in the F and H layers oxidized forms of dehydroabietic acid and sterols were abundant. The large proportion of dehydroabietic acid in the lipophilic fraction in the H layer suggests that it may be poorly degradable by soil microorganisms, probably because of its anti‐microbial function in trees. The composition of the acid‐soluble fraction indicated that the proportion of cellulose in relation to hemicelluloses increased from the litter layer to the F and H layers. Put together, changes in the relative proportions of organic compounds in soluble fractions indicate that selective preservation of compounds, litter input by plant roots and microbial synthesis of compounds all contribute to the accumulation of aliphatic compounds in the H layer of boreal forests.  相似文献   

Effects of Seasonal Nitrate Flush on Nitrogen Metabolism and Soluble Fractions Accumulation in Two Rice Varieties     

André Marques dos Santos  Elvia Mariam Lis Martinez Stark  Manlio Silvestre Fernandes  Sonia Regina de Souza 《Journal of plant nutrition》2013,36(9):1371-1384

ABSTRACT

Two rice varieties, ‘Piaui’ (a landrace) and ‘IAC-47’ (an improved variety), were grown in nutrient solution containing 20 mg nitrate (NO₃ ^?)-nitrogen (N) L^{? 1} up to 32 days after germination (DAG). After this, a group of plants received 200 mg NO₃ ^?NL^{? 1}, while the other was kept at 20 mg NO₃ ^?NL^{? 1} up to 42 DAG. From 42 until 56 DAG, all plants received 5 mg NO₃ ^?NL^{? 1}. Plants were collected at 42 and 56 DAG, soluble fractions, nitrate reductase (NR) and GS enzymatic activities were determined. The nutritional history of the plants affected significantly the uptake and use of nitrogen (N), and should be taken into consideration in the studies of N-use efficiency. The variety ‘Piaui’ was more efficient than ‘IAC-47’ in N-uptake use, accumulating more NO₃ ^? in its tissues at the initial phases of its cycle for subsequent utilization.  相似文献   

Clearance of para-aminohippuric acid in wethers consuming locoweed     

JR Strickland  MA Custis  AK Ashley  LL Smith  JL Klotz  CR Krehbiel 《New Zealand veterinary journal》2013,61(5):288-292

AIM: To validate the use of para-aminohippuric acid (PAH) as a marker for measuring blood flow in wethers consuming a mixed diet of locoweed and blue grama hay.

METHODS: Fourteen sheep, stratified by bodyweight (BW), were assigned to one of three treatments: 0.8 mg swainsonine (SW)/kg BW (HI), 0.2 mg SW/kg BW (LO), and no SW (Control). Sheep were fed various ratios of locoweed and blue grama hay to deliver SW treatments, for 28 days prior to infusion of PAH. Concentrations of SW and activities of alkaline phosphatase (Alk-P) and aspartate aminotransferase (AST) in serum were measured to confirm exposure to SW and subclinical intoxication. A single 20-ml injection of 5% PAH was delivered into the jugular vein after subclinical intoxication had been achieved. Blood samples were collected and serum analysed for PAH immediately prior to injection, then every 5 min from 5–30 min, and every 10 min from 30–60 min, following injection of PAH.

RESULTS: Effective delivery of SW was evident from the greater concentrations of SW measured in the serum of HI compared with LO animals (p<0.05). No significant differences were detected in the rate of elimination (range 0.097–0.108 L/min), elimination half-life (range 6.62–7.24 min), apparent volume of distribution for the central compartment (range 7.14–9.72 L), and clearance (range 0.73–0.92 L/min) of PAH, between treatments.

CONCLUSIONS: Subclinical intoxication with SW did not affect the pharmacokinetics of PAH. Thus, use of downstream dilution of PAH is a valid method to determine the rate of blood flow in nutrient flux experiments that involve consumption of locoweed.  相似文献   

Puumala Virus Outbreak in Western Thuringia,Germany, 2010: Epidemiology and Strain Identification     

M. Faber  T. Wollny  M. Schlegel  K. M. Wanka  J. Thiel  C. Frank  D. Rimek  R. G. Ulrich  K. Stark 《Zoonoses and public health》2013,60(8):549-554

In 2010, the highest annual number of human Puumala virus (PUUV) infections was reported in Germany since hantavirus surveillance started in 2001. The increase in annual case numbers was especially marked in western Thuringia. We combined results of case‐based hantavirus surveillance in humans and serological and molecular investigations in the rodent reservoir to describe the epidemiological situation and to identify the putative outbreak strain. A 5‐fold increase in notified hantavirus cases compared to the previous annual maximum was observed in western Thuringia in 2010. Disease incidence varied tremendously within a small geographical area with case patients' places of residence clustering around beech‐dominated broad leaf forest patches. Investigations in the rodent reservoir revealed a novel Puumala virus (PUUV) subtype, which is clearly distinct from strains collected in other PUUV endemic regions of Germany. It can be assumed that in regions in western Thuringia where hantavirus cases occurred in 2010 or previous outbreak years, PUUV has been present in the environment for a long time. Further studies are needed to elucidate the population dynamics and hantavirus prevalence of the rodent reservoir and driving ecological factors.  相似文献   

Optimal allocation of limited water supplies for Russet Burbank potatoes     

J. C. Stark  I. R. McCann 《American Journal of Potato Research》1992,69(7):413-421

Water shortages in many potato-producing regions have increased the demand for information on irrigating potatoes with limited water supplies. Field studies were conducted at Aberdeen, Idaho in 1988 and 1989 to determine the optimal allocation of limited water supplies for Russet Burbank potatoes. Irrigation amounts equal to 60 or 80% of estimated seasonal evapotranspiration (ET) were applied using various patterns of water allocation. Irrigation deficits were either partitioned evenly over the entire tuber bulking period, or were imposed during two of three designated growth stages (early, mid or late bulking) corresponding to the periods from 0 to 3, 3 to 6, and 6 to 9 weeks after tuber initiation, respectively. A well-watered, 100% ET check was included for comparison. Total yield reductions were greater when irrigation deficits were imposed during the early-mid and midlate bulking sequences than when they were imposed evenly over the entire tuber bulking period or during the early-late bulking sequence. Results relating U.S. No. 1 yields to seasonal water allocation patterns were similar to those for total yield. However, U.S. No. 1 yield reductions were proportionately greater. Irrigation deficits imposed during the early-mid bulking sequence resulted in the lowest specific gravities and the highest percentages of dark ends.  相似文献