Determination of cotton nitrogen status with a handheld chlorophyll meter     

C.W. Wood  P.W. Tracy  D.W. Reeves  K.L. Edmisten 《Journal of plant nutrition》2013,36(9):1435-1448

The ability of a hand‐held chlorophyll meter (SPAD‐502 Chlorophyll Meter³, Minolta Camera Co., Ltd., Japan) to determine the N status of cotton (Gossypium hirsutum L.) was studied at field sites in Alabama and Missouri. Meter readings on the uppermost fully‐expanded leaf were compared to leaf‐blade N and petiole NO₃‐N at first square, first bloom and midbloom as to their seed cotton yield predictive capability. Nitrogen was applied at rates of 0, 45, 90, 135, 180 and 225 kg ha^‐1 to establish a range of cotton chlorophyll levels, tissue N concentrations, and seed cotton yields. A typical curvilinear cotton yield response to N fertilizer was observed in Alabama experiments.

Because of adverse weather conditions, cotton yield in Missouri experiments did not respond to N. Chlorophyll meter readings were significantly correlated to leaf‐blade N concentration at all three stages of growth for all experiments. In Alabama, chlorophyll meter readings compared favorably to leaf‐blade N and petiole NO₃‐N with respect to their seed cotton yield predictive capability at all three stages of growth. It appears that hand‐held chlorophyll meters would be as reliable as leaf‐blade N and petiole NO₃‐N for predicting supplemental N fertilization requirements of cotton. However, more research will be required prior to use of chlorophyll meter readings for routine cotton‐N recommendation purposes.  相似文献   

The effects of a dietary antimicrobial on the biological half-life of chenodeoxycholic acid and plasma bile acid concentration patterns in the young pig     

J D Tracy  R V Allhands  D C Savage  A H Jensen 《Journal of animal science》1986,62(4):997-1004

Carbodox (CX), an antimicrobial agent, was fed at 0 or 58 ppm in a 19.5% crude protein corn-soybean metal diet to young pigs (12 to 15 kg). Radiolabeled chenodeoxycholic acid (CDC) was infused into the hepatic portal vein; after each of the subsequent six meals, blood samples were collected from the anterior vena cava (VC) and the hepatic portal (HP) veins. For the first 5 min after CDC infusion, the level of radioactivity in the CX pigs was significantly lower in the HP plasma and the slopes of the two curves of the plasma activity for the first hours were significantly different. The plasma bile acid concentrations (as measured by radioactivity) were significantly higher in the CX-treated animals following all meals. The biological half-life of CDC was 6.4 d in the controls and 5.7 d in the CX pigs. The increased rate of excretion was significant. These data indicate that bile acid metabolism in the young pig was significantly affected by feeding a subtherapeutic level of the antimicrobial CX.  相似文献   

IMAGING DIAGNOSIS—A CASE OF SPONTANEOUS HEPATIC PORTAL VEIN GAS IN AN 11‐MONTH‐OLD WEST HIGHLAND WHITE TERRIER          下载免费PDF全文

Jennifer A. Cartwright  Craig Breheny  Alison C. Major  Tracy L. Hill  Adam G. Gow 《Veterinary radiology & ultrasound》2016,57(5):E54-E57

An 11‐month‐old female entire West Highland White Terrier presented for chronic diarrhea with acute deterioration in demeanor and progression to systemic inflammatory response syndrome. Transcutaneous abdominal ultrasonography identified colonic ulceration and secondary mucosal gas. Suspected hepatic portal vein gas and hepatic parenchyma gas were also visualized. The patient was stabilized and managed for ulcerative colitis. Based on endoscopic biopsies, the dog was diagnosed with severe, chronic, pyogranulomatous colitis. On repeat ultrasonographic evaluation the portal vein and hepatic gas had resolved but the patient deteriorated and was ultimately euthanized due to sepsis.  相似文献   

Multi‐Center Retrospective Evaluation of Screw and Polymethylmethacrylate Constructs for Atlantoaxial Fixation in Dogs          下载免费PDF全文

Megan W. Stout Steele  Amy W. Hodshon  Andrew L. Hopkins  Gaemia M. Tracy  Noah D. Cohen  Sharon C. Kerwin  C. Elizabeth Boudreau  William B. Thomas  Joseph M. Mankin  Jonathan M. Levine 《Veterinary surgery : VS》2016,45(7):909-915

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Variability among four refractometers for the measurement of urine specific gravity and comparison with urine osmolality in dogs     

Adam J. Rudinsky  Maxey Wellman  Gaemia Tracy  Lisa Stoltenberg  Stephen P. DiBartola  Dennis J. Chew 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2019,48(4):702-709

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Dogs with acute myeloid leukemia or lymphoid neoplasms (large cell lymphoma or acute lymphoblastic leukemia) may have indistinguishable mediastinal masses on radiographs          下载免费PDF全文

Erin Epperly  Kelly R. Hume  Steven Moirano  Tracy Stokol  Joanne Intile  Hollis N. Erb  Peter V. Scrivani 《Veterinary radiology & ultrasound》2018,59(5):507-515

Acute myeloid leukemia is an uncommon hematopoietic neoplasm of dogs that should be differentiated from lymphoid neoplasms, such as lymphoma, because of different treatment protocols and a worse prognosis. Thoracic radiography is performed frequently in dogs with suspected hematopoietic neoplasia, and detecting a mediastinal mass often prioritizes lymphoma as the most likely diagnosis. However, we have observed a mediastinal mass in several dogs with acute myeloid leukemia and hypothesized that (1) the frequency of a mediastinal mass was higher and (2) the size of the mass was larger in dogs with acute myeloid leukemia compared to dogs with lymphoid neoplasms. In this analytical study (observational, retrospective, and cross‐sectional), the sample population included 238 dogs with hematopoietic neoplasia. These dogs were divided into lymphoid (large cell lymphoma, acute lymphoblastic leukemia) and myeloid groups based on standard phenotyping tests. A mediastinal mass was detected during thoracic radiography in 73/218 (33%) and nine of 20 (45%) dogs in the lymphoid and myeloid groups (P = 0.21), respectively. The median size ratio of mediastinal mass to cardiac silhouette was 0.20 and 0.23 in the lymphoid and myeloid groups (P = 0.96), respectively. Additionally, we observed normal thoracic radiographs in 111/218 (51%) dogs in the lymphoid group and nine of 20 (45%) dogs in the myeloid group. In conclusion, acute myeloid leukemia should be considered when a mediastinal mass is detected during radiography in dogs with suspected hematopoietic neoplasia—but the presence or size of a mediastinal mass does not differentiate between myeloid and lymphoid neoplasms.  相似文献   

Microbiology. Mycobacteria's export strategy     

Ize B  Palmer T 《Science (New York, N.Y.)》2006,313(5793):1583-1584

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Cell wall composition in juvenile and adult leaves of maize (Zea mays L.)     

Abedon BG  Hatfield RD  Tracy WF 《Journal of agricultural and food chemistry》2006,54(11):3896-3900

Many leaf characteristics vary with position along the culm in maize (Zea mays L.) due to the existence of vegetative phase change and heteroblasty. The objective of this work was to determine if differences in cell wall composition exist among developmental phases and between Cg1, a developmental mutant, and wild-type maize. In one experiment, the middle third of fully elongated leaf blades from lower and upper regions of the shoot was harvested (midribs removed) and analyzed for several cell wall components. Averaged over five inbreds (De811, Ia5125, Mo17, P39, and Wh8584), lower leaf blades had higher levels of xylose and lower levels of total uronosyls, glucose, arabinose, and galactose (P < 0.05) than did upper leaf blades. With the exception of glucose, upper and lower leaves of Cg1 plants varied in the same manner as their near-isogenic siblings, except cell walls of Cg1 plants were more "juvenile" than cell walls of wild-type siblings at the same leaf stage. These data support the hypothesis that Cg1 delays but does not eliminate the transition from juvenile-vegetative to adult-vegetative phase. In a second experiment, juvenile (leaves 3 and 5), transition (leaf 7), and adult (leaves 9 and 11) leaves from inbreds B73 and De811 were harvested and analyzed as in the first experiment. As leaf number rose, total cell wall content of sample dry matter, total neutral sugars, glucose, xylose, and ester-linked monomers of p-coumaric acid and total ferulates including ferulate dimers increased linearly while total uronosyls acids, arabinose, and galactose declined linearly (P < 0.05). Glucose and xylose are major cell wall components released from cellulose and xylans after acid hydrolysis. Pectin, a minor component of grass cell walls, is composed of galacturonosyls, arabinose, and galactose. Secondary cell wall deposition increased between leaves 3 and 11 in a heteroblastic series, due to either increased cell wall content concomitant with decreased cell lumen size, changes in proportion of cell types (i.e., sclerenchyma), or a combination of these factors.  相似文献   

Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Lightning Injuries     

Chris Davis  Anna Engeln  Eric Johnson  Scott E. McIntosh  Ken Zafren  Arthur A. Islas  Christopher McStay  William ‘Will’ R. Smith  Tracy Cushing 《The Forestry Chronicle》2012,23(3):260-269

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Opening and closing of the bacterial RNA polymerase clamp     

A Chakraborty  D Wang  YW Ebright  Y Korlann  E Kortkhonjia  T Kim  S Chowdhury  S Wigneshweraraj  H Irschik  R Jansen  BT Nixon  J Knight  S Weiss  RH Ebright 《Science (New York, N.Y.)》2012,337(6094):591-595

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