The effect of seed source, light during germination, and cold-moist stratification on seed germination in three species of Echinacea for organic production     

Romero FR  Delate K  Hannapel DJ 《HortScience : a publication of the American Society for Horticultural Science》2005,40(6):1751-1754

Organic production of one of the most popular botanical supplements, Echinacea, continues to expand in the U.S. Echinacea seeds typically show a high degree of dormancy that can be broken by ethephon or gibberelic acid (GA), but these methods are currently disallowed in organic production. In order to determine the efficacy of non-chemical seed treatments, we evaluated the effect of varying seed source and supplying light, with and without cold-moist stratification, on seed germination of the three most important medicinal species of Echinacea, E. angustifolia DC, E. purpurea (L) Moench, and E. pallida (Nutt.) Nutt. Treatments included cold-moist stratification under 24 h light, 24 h dark, and 16/8 h light/dark to break seed dormancy. We found that germination was greater in the E. purpurea and E. pallida seeds from a commercial organic seed source compared to a public germplasm source. When seeds were not cold-moist stratified, 16-24 h light increased germination in E. angustifolia only. Echinacea angustifolia, E. purpurea, and E. pallida seeds that were cold-moist stratified under 16-24 h of light for 4 wk had a significantly greater percentage and rate of germination compared to seeds germinated in the dark. Therefore, cold-moist stratification under light conditions is recommended as a method to break seed dormancy and increase germination rates in organic production of Echinacea.  相似文献   

MAGNETIC RESONANCE IMAGING FEATURES OF MULTILOBULAR OSTEOCHONDROSARCOMA IN 3 DOGS     

David  Lipsitz  DVM  Robin E.  Levitski  DVM  Wayne L.  Berry  BVSc  MMedVet 《Veterinary radiology & ultrasound》2001,42(1):14-19

Three dogs with multilobular osteochondrosarcoma of the skull were evaluated using magnetic resonance (MR) imaging. Spin echo T1, T2, proton weighted and post contrast T1W images were obtained with a 1.5 Tesla magnet. The MR imaging findings were similar in all three dogs with mixed signal intensities in the T1W, T2W and proton weighted images and fairly large areas of contrast enhancement in the post contrast T1W images. The extent of brain and soft tissue involvement were well delineated and provided useful information concerning surgical planning. MR imaging provided a useful method of evaluating dogs with skull tumors.  相似文献   

RADIOGRAPHIC FINDINGS OF CANINE DYSAUTONOMIA IN TWENTY-FOUR DOGS     

David A.  Detweiler  David S.  Biller  DVM  James J.  Hoskinson  DVM  Kenneth R.  Harkin  DVM 《Veterinary radiology & ultrasound》2001,42(2):108-112

Canine dysautonomia is an idiopathic condition resulting in loss of autonomic nervous system function. Recently, the prevalence of dogs diagnosed with dysautonomia in the mid-western United States has increased. In this study the medical records and radiographic findings in 24 dogs with dysautonomia were reviewed. A diagnosis of dysautonomia was made in 17 (71%) of the dogs in this study by postmortem examination, the remaining 7 (29%) dogs were diagnosed pharmacologically. The radiographic findings supportive of dysautonomia include aspiration pneumonia, megaesophagus, or a distended stomach, small bowel, or urinary bladder. In some instances, the disease radiographically mimicked other disorders of the gastrointestinal tract, including mechanical obstruction.  相似文献   

Long-term lack of transmission of Aujeszky's disease virus (ADV) in a chronically infected Swedish weaner pig producing herd     

Marie Engel  David W. Hird  Tim E. Carpenter  Martin Wierup 《Preventive veterinary medicine》1995,24(4):245-252

A cohort of 53 swine seronegative to Aujeszky's disease virus (ADV) was monitored in a 1 year study of a chronically infected commercial Swedish weaner pig producing herd. Serum samples were acquired from all 134 adult swine and analyzed by enzyme-linked immmunosorbent assay (ELISA). Animals testing negative, along with introduced replacement gilts, were followed serologically every second month. Movements of animals were recorded for 319 days and exposure to seropositive animals was calculated for each seronegative pig in the cohort. The accumulated daily pig contact between the 53 ADV-non-infected swine and 43 infected swine was 35 660 days and the median number of days in contact for the non-infected swine with infected was 222. Despite the frequent contact with seropositive pigs, no seronegative animals seroconverted during the first 11 months of observation. Forty-six of 53 pigs seroconverted after a clinical outbreak during the twelfth month of observation.  相似文献   

MAGNETIC RESONANCE IMAGING OF THE EQUINE STIFLE     

Susan J.  Holcombe  VMD  MS  Alicia L.  Bertone  DVM  PhD  David S.  Biller  DVM  Valerie  Haider  DVM 《Veterinary radiology & ultrasound》1995,36(2):119-125

The purpose of this study was to define normal gross anatomic structures in the equine stifle with magnetic resonance images. Magnetic resonance (MR) images were made in sagittal, 15° supinated, transverse, and dorsal planes of two equine stifles. The MR images were scrutinized by comparing MR images to dissection specimens and frozen cross sections of stifle joints. Sagittal and 15° supinated images were the most valuable in assessing articular cartilage, subchondral bone, and soft tissue structures within the joint. Cranial and caudal cruciate ligaments, medial and lateral menisci, meniscotibial and meniscofemoral ligaments, long digital extensor tendon, and patellar ligaments were easily evaluated. MR images provided substantially more gross anatomical information than the currently available imaging modalities.  相似文献   

Response to Liposome-Encapsulated Doxorubicin (TLC D-99) in a Dog With Myeloma     

William C. Kisseberth  E. Gregory MacEwen  Stuart C. Helfand  David M. Vail  Cheryl L. London  Evan Keller 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1995,9(6):425-428

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Effects of heartworm and intestinal parasitic infections on hematology and peripheral lymph node cytology in louisiana dogs     

Gossett KA  Root CR  Cleghorn B  Church GE  Turk JR  Turk MA 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1987,16(4):97-101

Hookworm infected dogs had higher blood basophil counts than hookworm negative dogs. Dogs with occult heartworm infection (i.e., without microfilaremia) had higher blood neutrophil counts than heartworm negative dogs. The percentage of eosinophils in peripheral lymph nodes was higher in heartworm infected, microfilaremic dogs than in both occult infected dogs and heartworm negative dogs. Heartworm or intestinal parasitic infection had no other significant effects on hematologic parameters or peripheral lymph node cytology.  相似文献   

A plea for broader advertising of positions in international veterinary medicine          下载免费PDF全文

David Green P 《The Canadian veterinary journal. La revue veterinaire canadienne》1979,20(12):364

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Semiconductor alternating-current motor drives and energy conservation     

Bendaniel DJ  David EE 《Science (New York, N.Y.)》1979,206(4420):773-776

The concentration of electrical energy usage in alternating-current motor drives presents an opportunity for substantial conservation. Emerging advances in power semiconductor transistor systems will support a major commerical effort to this end. An alternating-current synthesizer for this purpose may soon be available. The synthesizer produces electricial power of variable and programmable frequency, voltage, and wave form so that performance can be optimized. This technology provides the additional opportunity for fundamental improvements in electrical distribution and usage systems in the longer term. Power processing with semiconductor a-c motor controls is expected to become widespread in the near future.  相似文献   

Mode of action of the systemic fungicides furalaxyl,metalaxyl and ofurace     

David J. Fisher  Ann L. Hayes 《Pest management science》1982,13(3):330-339

The systemic fungicides furalaxyl, metalaxyl and ofurace,

1 Ofurace is the proposed BSI and ISO common name for α-(2-chloro-N-2,6-xylylacetamido)-γ-butyrolactone.

used to control diseases caused by phycomycetes, were extremely active in vitro against Pythium ultimum, Phytophthora nicotianae and Phytophthora palmivora. Sporangia production was reduced more than mycelial growth but germination of sporangia and zoospores was relatively unaffected. Less than 1% of the metalaxyl or furalaxyl, present in media at the ED₅₀ for hyphal growth, was firmly absorbed by Phyt. palmivora mycelium; uptake was against a concentration gradient and was characterised by a rapid accumulation followed by a more gradual release. Respiration and wall synthesis were not inhibited, whilst membrane permeability was unaffected. Lipid patterns were altered but these changes were probably of secondary importance. The fungicides inhibited protein and nucleic acid synthesis; RNA production was particularly affected. There was some evidence of a reduction in nuclear division. The primary effect of furalaxyl and metalaxyl probably involves impaired biosynthesis of RNA so that mitosis is inhibited; ofurace may act in the same way.  相似文献