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   

Neurological,imaging and pathological features of a meningeal inflammatory pseudotumour in a Maltese terrier     

S. Loderstedt  G. L. Walmsley  B. A. Summers  R. Cappello  H. A. Volk 《The Journal of small animal practice》2010,51(7):387-392

A five-year eight-month-old Maltese terrier was presented with a 3-week history of progressive paraparesis and pelvic limb ataxia. Neurological examination was consistent with a lesion involving the T3-L3 spinal cord segments. Myelogram and magnetic resonance imaging revealed a spherical, intradural-extramedullary mass lesion at T13/L1. A dorsal laminectomy, durotomy and debulking of the mass were performed. Histopathologic examination revealed a highly cellular tissue, most likely of mesenchymal origin, infiltrated by many lymphocytes, macrophages and neutrophils. The pathological diagnosis of an inflammatory pseudotumour was made. Postsurgical analgesia was achieved with opioids and 2 mg/kg carprofen twice daily for 5 days. When the histopathological diagnosis was made, a tapering course of 1 mg/kg prednisolone twice daily was prescribed, with dose reduction by approximately 50% every 4 to 6 weeks over a 4-month period. Magnetic resonance imaging was repeated at 22, 32 and 85 weeks postsurgery; no signs of regrowth could be detected and the patient recovered with residual mild paraparesis. Inflammatory pseudotumour has not been documented previously at this site in dogs and, although rare, should be considered in the differential diagnosis of a focal mass lesion affecting the spinal cord. Surgical debulking and immunomodulatory therapy can be curative.  相似文献   

The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor   总被引：1，自引：0，他引：1  

GM Keating  SW Bougher  RW Zurek  RH Tolson  GJ Cancro  SN Noll  JS Parker  TJ Schellenberg  RW Shane  BL Wilkerson  JR Murphy  JL Hollingsworth  RM Haberle  M Joshi  JC Pearl  BJ Conrath  MD Smith  RT Clancy  RC Blanchard  RG Wilmoth  DF Rault  TZ Martin  DT Lyons  PB Esposito  MD Johnston  al et 《Science (New York, N.Y.)》1998,279(5357):1672-1676

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.  相似文献   

The vulnerability of US apple (Malus) genetic resources     

Gayle M. Volk  C. Thomas Chao  Jay Norelli  Susan K. Brown  Gennaro Fazio  Cameron Peace  Jim McFerson  Gan-Yuan Zhong  Peter Bretting 《Genetic Resources and Crop Evolution》2015,62(5):765-794

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Living snow fences show potential for large storage capacity and reduced drift length shortly after planting     

Justin P. Heavey  Timothy A. Volk 《Agroforestry Systems》2014,88(5):803-814

Living snow fences are windbreaks designed to mitigate blowing snow problems by trapping snow in drifts before it reaches a road. Research studies on living snow fences are limited and extension publications consequently lack precise design protocols. This study investigated 18 sites in New York State planted with living snow fences of various vegetation types and ages ranging from 1 to 11 years after planting. Key plant growth variables of fence height and optical porosity were measured along with distance upwind and downwind. This data was combined with site specific snowfall estimates and established equations to calculate the snow storage capacity of each fence, average annual snow transport (blowing snow) at each site, and length of the downwind drift. Capacity/transport ratio of each fence/site was identified as a key variable. Height increased linearly over time and porosity decreased. Three years after planting, height and porosity was sufficient so that capacity/transport ratios were greater than 1:1, indicating substantial snow trapping potential much sooner than commonly reported. Four to eleven years after planting, capacity/transport ratios were between 3:1 and 110:1. Capacity/transport ratios of 15:1 or greater occurred as early as 5 years after planting and were correlated with estimated drift lengths <10 m. The influence of capacity/transport ratio on drift length is not accounted for in current publications and setback recommendations range from 30 to 180 m. The results of this study can improve the understanding, design and function of living snow fences.  相似文献   

Signalment,Clinical Presentation,and Diagnostic Findings in 122 Dogs with Spinal Arachnoid Diverticula     

D.A. Mauler  S. De Decker  L. De Risio  H.A. Volk  R. Dennis  I. Gielen  E. Van der Vekens  K. Goethals  L. Van Ham 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(1):175-181

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Sonic agglomeration of aerosol particles     

Michael Volk Jr.  William J. Moroz 《Water, air, and soil pollution》1976,5(3):319-334

Carbon black was used to study the behavior of an aerosol in a sound field. The primary objective of this work was to determine the feasibility of using sonic agglomeration at low sound pressure levels (100 to 120 dB) to coagulate particles. If coagulation could be achieved, the larger particles could be collected in a subsequent removal device. Prediction of optimum conditions for maximum agglomeration was also an integral part of this analysis.Separate experiments to determine the effect of varying sound pressure level, frequency, particle mass loading in an air stream, and exposure time were conducted. Increasing the mass loading, sound pressure level and exposure time resulted in increased agglomerate size. For all tests using carbon black, optimum growth occurred at 3 kHz. It is noted that the mean particle diameter in a carbon black aerosol can be increased an order of magnitude using sonic agglomeration at low sound pressure levels suggesting that this mechanism can be used effectively in industrial processes.  相似文献   

Epidemiology of recurrent seizure disorders and epilepsy in cats under primary veterinary care in the United Kingdom     

Dan Gerard O'Neill  Stephanie A. Phillipps  Jordon R. Egan  David Brodbelt  David B. Church  Holger A. Volk 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(6):2582-2594

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Can breeding strategies modify or eliminate the syringomyelia phenotype?     

Driver CJ  Volk HA 《The Veterinary record》2011,169(26):679-680

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Canine intracranial neoplasia: clinical risk factors for development of epileptic seizures     

Schwartz M  Lamb CR  Brodbelt DC  Volk HA 《The Journal of small animal practice》2011,52(12):632-637

Objectives : To identify clinical risk factors for seizures in dogs with intracranial neoplasia. Methods : A cross‐sectional retrospective study of 68 dogs with histopathologically confirmed primary or secondary intracranial neoplasia, complete clinical history and magnetic resonance imaging of the brain was conducted. Signalment and clinical history were retrieved from clinical records and magnetic resonance images of the brain were re‐evaluated. Prevalence of findings was compared between dogs with and without seizures. Results : Forty‐two dogs had tumour‐related seizures, the remaining 26 were seizure‐free. Tumour types included meningioma (23 dogs with and 5 without seizures), glioma (9 dogs with and 6 without seizures), choroid plexus tumour (2 dogs without seizures), neuroblastoma (1 dog with seizures) and metastatic/invasive tumours including lymphoma (9 dogs with and 13 without seizures). On the basis of multi‐variable logistic regression analysis, risk factors for seizures associated with intracranial neoplasia were magnetic resonance imaging findings consistent with the presence of neoplastic tissue in frontal lobe [odds ratio (OR) 9·61; 95% confidence interval (CI) 2·59 to 35·61], marked gadolinium enhancement (OR 10·41; 95% CI 2·07 to 52·30) and magnetic resonance imaging findings of subfalcine and/or subtentorial herniation (OR 3·88; 95% CI 1·10 to 13·71). Clinical Significance : Dogs with primary or secondary intracranial neoplasia are at risk of seizures, particularly those with tumours that affect the frontal lobe, enhance markedly with gadolinium, or cause subfalcine and/or subtentorial herniation.  相似文献