scholarly journals Distribution of Xanthomonas hortorum pv. carotae Populations in Naturally Infested Carrot Seed Lots

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2144-2148 ◽  
Author(s):  
Jeness C. Scott ◽  
Jeremiah K. S. Dung
Keyword(s):  
Daucus Carota ◽  
Bacterial Blight ◽  
Limit Of Detection ◽  
Plant Pathogenic Bacterium ◽  
Nonnormal Distributions ◽  
Individual Seed ◽  
Seed Health ◽  
Seedborne Disease ◽  
Carrot Seed ◽  
The Mean

Bacterial blight of carrot (Daucus carota subsp. sativus), caused by the plant-pathogenic bacterium Xanthomonas hortorum pv. carotae, is a common seedborne disease of carrot wherever the crop is grown. Carrot seed lots were evaluated to determine the variability and distribution of populations of X. hortorum pv. carotae among individual carrot seeds. Twenty-four carrot seed lots harvested between 2014 and 2016 were subjected to a bulk seed wash dilution-plate assay to obtain mean X. hortorum pv. carotae levels. Mean infestation levels resulting from the bulk seed wash assays among the 24 seed lots ranged from 1.2 × 107 and 9.6 × 108 CFU/g seed and averaged 3.6 × 108 CFU/g seed. Individual seeds from the same 24 lots were also tested with a scaled-down wash assay of individual seeds. Among the 1,380 seeds that were individually assayed, 475 X. hortorum pv. carotae-positive seeds were detected (34.4%). Rates of X. hortorum pv. carotae detection on individual seed in seed lots ranged from 0% (not detected) to 97.9%, and the mean and median X. hortorum pv. carotae population on an individual seed was 8.3 × 104 and 6.3 × 101 CFU/seed, respectively. Among individual seeds, X. hortorum pv. carotae populations ranged from 2 (the limit of detection of the assay) to 3.6 × 107 CFU/seed. CFU data for 23 of the 24 seed lots were nonnormal and the Log-Logistic (3P) distribution best described populations of X. hortorum pv. carotae recovered from individual carrot seeds. The influence and impact of nonnormal distributions of X. hortorum pv. carotae in commercial carrot seed lots on seed health tests, seedborne transmission, and bacterial blight epidemiology requires further study.

scholarly journals Bacterial Blight in Carrot Seed Crops in the Pacific Northwest

Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 896-907 ◽  
Author(s):  
Lindsey J. du Toit ◽  
Fred J. Crowe ◽  
Mike L. Derie ◽  
Rhonda B. Simmons ◽  
Gary Q. Pelter
Keyword(s):  
Pacific Northwest ◽  
Seed Production ◽  
Daucus Carota ◽  
Bacterial Blight ◽  
Xanthomonas Campestris ◽  
The Pacific ◽  
Carrot Seed ◽  
Direct Seeded ◽  
Clean Seed ◽  
Seed Crops

Carrot (Daucus carota subsp. sativus) seed crops in Oregon and Washington were surveyed in 2001-02 and 2002-03 for development of Xanthomonas campestris pv. carotae, causal agent of bacterial blight. For each state and season, 20 plants were sampled from each of 7 to 12 direct-seeded crops twice in the fall or winter and three times from spring to summer; and from each of 2 to 4 steckling (root-to-seed) crops three times from spring to summer. X. campestris pv. carotae was detected in 1 of 15 and 6 of 32 stock seed lots planted in the fall in Oregon and Washington, respectively, and in 2 of 6 steckling shipments planted in each state in the spring. The pathogen was detected at 102 to 108 CFU/g foliage in 1 of 22 and 10 of 14 direct-seeded crops within 2 months of planting in 2001 and 2002, respectively. The prevalence of X. campestris pv. carotae then increased through the season in most seed crops, although bacterial blight symptoms were not observed until April in Oregon and July in Washington in both seasons. In August 2002 and 2003, X. campestris pv. carotae was detected in all 10 and 13 crops surveyed in Oregon, respectively; and in 11 of 12 and 7 of 10 crops in Washington, respectively. The pathogen was typically less prevalent in steckling versus direct-seeded crops. X. campestris pv. carotae was detected in 20 of 22 and 19 of 23 harvested seed lots in Oregon and Washington, respectively, at populations ranging from 1.3 × 101 to 1.4 × 108 CFU/g seed. Airborne X. campestris pv. carotae, detected ≤1,600 m downwind of crops being threshed in Oregon in September of 2003 and 2004, may provide a source of inoculum for newly planted seed crops between overlapping biennial seasons for carrot seed production. Despite the prevalence of this pathogen in the Pacific Northwest, carrot seed lots free of X. campestris pv. carotae were detected, demonstrating the ability to produce clean seed in this region by adhering to recommended practices for management of bacterial blight.

SERUM TRIIODOTHYRONINE DETERMINATION BY SATURATION ANALYSIS

1973 ◽  
Vol 72 (4) ◽  
pp. 714-726 ◽  
Author(s):  
A. Burger ◽  
B. Miller ◽  
C. Sakoloff ◽  
M. B. Vallotton
Keyword(s):  
Ionic Strength ◽  
Limit Of Detection ◽  
Improved Method ◽  
Accuracy Of Measurement ◽  
Tracer Amount ◽  
The Mean ◽  
Physiological Values ◽  
Hyperthyroid Patients ◽  
Solvent Blank

ABSTRACT An improved method for the determination of serum triiodothyronine (T3) has been developed. After addition of a tracer amount of the hormone, T3 was extracted from 1 ml serum under conditions of pH and ionic strength which favoured T3 extraction (89%) over thyroxine (T4) extraction (58%). Chromatography of the extracted material on Sephadex LH-20 separated T3 completely from residual T4. The T3 eluate was dried, then re-dissolved in 0.5 ml NaOH 0.04 n. To 0.2 ml duplicate aliquots, a standard amount of TBG was added for the competitive protein analysis. After one hour incubation at 4°C, separation of bound from free T3 was achieved on small Sephadex G-25 columns. Overall recovery was 67 ± 10.8% and correction for the loss was made. The solvent blank was 37 ± 27 (sd) ng/100 ml. Accuracy of measurement of known quantities of T3 added to serum was 98.4%. The coefficient of variation within the assay was 6.2% and between the assays it was 11.4%. The limit of detection (0.1 ng) corresponded to a concentration of 25 ng/100 ml. T4 added to serum did not interfere with T3 determination until high non-physiological values were reached. The mean ± sd serum T3 in 54 euthyroid subjects was 153 ± 58 ng/100 ml and in 24 hyperthyroid patients it was 428 ±186 ng/100 ml; 4 out of the 24 hyperthyroid values were within 2 sd of the mean euthyroid group. All the values found in the euthyroid group were well above the limit of detection of the method.

Consistency of long-term marketable yield of carrot and onion cultivars in muck (organic) soil in relation to seasonal weather

2010 ◽  
Vol 90 (5) ◽  
pp. 755-765 ◽  
Author(s):  
M. T. Tesfaendrias ◽  
M. R. McDonald ◽  
J. Warland
Keyword(s):  
Allium Cepa ◽  
Daucus Carota ◽  
Organic Soil ◽  
Data Sets ◽  
Fresh Market ◽  
Marketable Yield ◽  
Daucus Carota L ◽  
Weather Patterns ◽  
The Mean

To identify carrot and onion cultivars that provide consistent marketable yields, we tracked the yields of five fresh market carrot [(Daucus carota L. subsp. sativus (Hoffm.) Arcang.] and six onion (Allium cepa L.) cultivars for at least 13 yr. Relationships between long-term weather variables and marketable yields were also investigated. The effects of cultivar, year and cultivar × year interactions on yield of carrots and onions were assessed. Cultivar and year had significant effects on carrot and onion yields, while the interaction was significant in only one of four data sets of carrot yield. Carrot cv. Cellobunch (95.4 t ha–1) and onion cv. Corona (74.1 t ha–1) had the highest mean marketable yields over the years studied. There was a slight positive correlation between mean yield of the assessed carrots and maximum temperatures in September (r = 0.44). Mean carrot yield was also somewhat negatively correlated with total rainfall in July (r = –0.43) and with number of days with rain in August (r = –0.43) and September (r = –0.44). Most onion cultivars showed stronger relationships between marketable yield and various weather patterns. Marketable yield of onions increased with an increase in the number of days with rainfall in June (r = 0.57). The mean marketable yield of the six onion cultivars decreased in relation to temperatures ≥30°C in June (r = –0.55) and August (r = –0.53). The mean yield of all the onions in the trials was negatively correlated (r = –0.78) with growing degree days (base 5°C, May to August). The results indicated that the data from long-term cultivar trials can be used to identify cultivars that yield well despite seasonal variations in weather. Key words: Daucus carota, Allium cepa, temperature, rainfall

Comparison of Seed Transmission and Survival of Xanthomonas axonopodis pv. phaseoli and Xanthomonas fuscans subsp. fuscans in Common Bean Seeds

2013 ◽  
Vol 14 (1) ◽  
pp. 41 ◽  
Author(s):  
Y. He ◽  
G. P. Munkvold
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Bacterial Blight ◽  
Disease Incidence ◽  
Seed Transmission ◽  
Common Bacterial Blight ◽  
Phaseolus Vulgaris L ◽  
Transmission Frequency ◽  
Xanthomonas Axonopodis ◽  
Seed Health

Xanthomonas axonopodis pv. phaseoli (Smith) Vauterin (Xap) and Xanthomonas fuscans subsp. fuscans Schaad et al. (Xff) cause indistinguishable symptoms known as common bacterial blight of bean (Phaseolus vulgaris L.). These results confirm a higher disease incidence and seed transmission frequency of Xff compared to Xap and reinforce the need for seed health tests that can differentiate the two species. Accepted for publication 21 August 2013. Published 23 September 2013.

Specific 3H radioimmunoassay with a monoclonal antibody for monitoring cyclosporine in blood.

1988 ◽  
Vol 34 (2) ◽  
pp. 257-260 ◽  
Author(s):  
P E Ball ◽  
H Munzer ◽  
H P Keller ◽  
E Abisch ◽  
J Rosenthaler
Keyword(s):  
Monoclonal Antibody ◽  
Bone Marrow ◽  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Parent Drug ◽  
Sample Volume ◽  
Specific Radioimmunoassay ◽  
The Mean ◽  
Blood Specimens

Abstract A specific radioimmunoassay involving a mouse monoclonal antibody to cyclosporine has been developed for monitoring the parent drug in blood. Pretreatment with methanol removes cyclosporine from the erythrocytes. The limit of detection is about 12 micrograms/L, sample volume is 50 microL of blood, and within- and between-assay CVs are less than 7%. Assay results correlated well with those obtained by "high-performance" liquid chromatography (HPLC) for liver (n = 42), for heart (n = 64), for bone-marrow (n = 36), and for kidney (n = 140). For blood specimens obtained from patients treated with cyclosporine postoperatively for as long as 65 months, the mean RIA/HPLC ratio in all with transplant indications was close to 1. Therefore, the specific radioimmunoassay apparently can be used instead of HPLC to measure the parent drug in blood.

scholarly journals The relationship between fasting plasma concentrations of selected flavonoids and their ordinary dietary intake

2009 ◽  
Vol 103 (2) ◽  
pp. 249-255 ◽  
Author(s):  
Jie Cao ◽  
Ying Zhang ◽  
Wei Chen ◽  
Xiujuan Zhao
Keyword(s):  
Intervention Study ◽  
Dietary Intervention ◽  
Limit Of Detection ◽  
Plasma Concentrations ◽  
Protective Effects ◽  
Fasting Plasma ◽  
Dietary Intervention Study ◽  
Flavonoid Intake ◽  
The Mean ◽  
The Relationship

Epidemiological studies suggest that a diet high in flavonoids protects against chronic diseases such as CVD and cancer. The objective of the present study was to evaluate the relationship between the intake of quercetin, kaempferol, isorhamnetin, apigenin and luteolin and their corresponding plasma concentrations, and further to explore whether these flavonoids can serve as biomarkers of their intake. Flavonoid intake and their plasma concentrations were analysed in ninety-two subjects consuming their habitual diet. Flavonoid intake was estimated with 7-d dietary records using available data on the flavonoid content of food. Plasma flavonoid concentrations were quantified by HPLC. In addition, we undertook a dietary intervention study to investigate plasma apigenin concentration after the consumption of celery leaf. The mean intake estimates of quercetin, kaempferol, isorhamnetin, apigenin and luteolin amounted to 13·58, 14·97, 12·31, 4·23 and 8·08 mg/d, respectively. The corresponding mean plasma concentrations were 80·23, 57·86, 39·94, 10·62 and 99·90 nmol/l. The mean 7 d intake of five flavonoids was positively correlated to their corresponding plasma concentrations, with correlation coefficients ranging from 0·33 to 0·51 (P < 0·05). In the dietary intervention study, the plasma apigenin concentration rose after celery leaf ingestion, and fell within 28 h to below the limit of detection (2·32 nmol/l). The present results suggest that quercetin, kaempferol, isorhamnetin, apigenin and luteolin are bioavailable from the diet. The levels of fasting plasma flavonoids seem to be suitable biomarkers of short-term intake. The combination of plasma flavonoids with their intake may prove useful when the possible health-protective effects of flavonoids are studied.

Estimating the Mean, Variance, and Confidence Limits from Censored (

AIHAJ ◽  
1990 ◽  
Vol 51 (8) ◽  
pp. 416-419 ◽  
Author(s):  
JIMMY L. PERKINS ◽  
GARY N. CUTTER ◽  
MICHAEL S. CLEVELAND
Keyword(s):  
Limit Of Detection ◽  
Confidence Limits ◽  
Exposure Data ◽  
The Mean ◽  
Mean Variance

Performance Evaluation of CEA Assay on Beckman Coulter UniCel DxI 800

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S20-S20
Author(s):  
Qing Wei ◽  
Robert Hardy ◽  
Liyun Cao
Keyword(s):  
Reference Range ◽  
Limit Of Detection ◽  
Measurement Range ◽  
Surgical Removal ◽  
Primary Colorectal Cancer ◽  
Serum Cea ◽  
The Mean ◽  
Precision And Accuracy ◽  
Patient Prognosis ◽  
High Level

Abstract Carcinoembryonic antigen (CEA) is a glycoprotein normally found in embryonic entodermal epithelium. Increased levels may be found in patients with primary colorectal cancer or other malignancies. CEA levels are not useful in screening the general population for undetected cancers. However, CEA levels provide important information about patient prognosis, recurrence of tumors after surgical removal, and effectiveness of therapy. The aim of this study was to assess the analytical performance of CEA assay on a Beckman Coulter UniCel DxI 800. The linearity, sensitivity, reference range, precision, and accuracy were evaluated following CLSI guidelines. The within-run and between-run precisions were assessed by analyzing QC material at low and high levels of concentrations. The accuracy was assessed by comparison of 152 patient serum CEA on DXI with CEA on a previously established ADVIA Centaur System. The analytical measurement range was determined to be linear between 0.00 and 951.3 ng/mL with a slope of 0.976 and intercept of 0.075. The limit of blank (LOB) was determined as 0.03 ng/mL and the limit of detection (LOD) was 0.1 ng/mL. The reference range was verified as 0.0 to 3.0 ng/mL (nonsmokers) and 0.0 to 5.0 ng/mL (smokers). The within-run CVs for CEA were 4.4% at the low level of 2.239 ng/mL and 2.5% at the high level of 38.1 ng/mL. The between-run CVs at low and high levels were 4.4%, and 4.0%, respectively. Comparison of CEA on the Beckman Coulter UniCel DxI 800 with CEA on the ADVIA Centaur System of 152 patient samples showed the slope was 1.541 (95% CI, 1.515-1.567) with an intercept of 0.17 and a correlation coefficient of 0.9943 (Deming). The mean bias between Beckman and ADVIA was 6.49 (41.71%). In summary, our data demonstrate that CEA assay on the Beckman Coulter UniCel DxI 800 has good linearity and precision. There is also good correlation between CEA tested on the Beckman Coulter UniCel DxI 800 and on the ADVIA Centaur System with a positive bias.

Pharmacokinetic Evaluation of a Fibrinogen Concentrate in Patients with Congenital Fibrinogen Deficiency.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2268-2268 ◽  
Author(s):  
Marilyn J. Manco-Johnson ◽  
Giancarlo Castaman ◽  
Sandra Fremann ◽  
Sigurd Knaub ◽  
Gavino Piseddu ◽  
...  
Keyword(s):  
Body Weight ◽  
Limit Of Detection ◽  
Secondary Analysis ◽  
Surrogate Endpoint ◽  
Activity Levels ◽  
Fibrinogen Concentrate ◽  
Relevant Effect ◽  
Efficacy Parameter ◽  
Post Infusion ◽  
The Mean

Abstract BACKGROUND: Congenital fibrinogen deficiency is a rare bleeding disorder and comprises fibrinogen abnormalities that result in either reductions in the quantity (hypofibrinogenemia and afibrinogenemia) or structure and functionality (dysfibrinogenemia) of fibrinogen. The pharmacokinetics (PK) and surrogate efficacy of a plasma-derived fibrinogen concentrate was studied in a prospective, open, non-controlled, multinational clinical study in patients with confirmed afibrinogenemia. METHODS: Patients had to have &lt; 0.20 g/L plasma fibrinogen activity, be in a non-bleeding state and receive a single dose of 70 mg/kg body weight. Maximum clot firmness (MCF), determined via validated thrombelastography (TEG), was used as a surrogate endpoint for hemostatic efficacy. Standard PK parameters were analyzed in a central laboratory with a validated Clauss assay and an ELISA. RESULTS: A total of 15 patients were treated at 10 centers in the US and Italy. Of these, 5 (33.3%) were female. The mean age was 30 years, with 11 subjects (73.3%) in the age group of 16 to &lt;65 years and the remaining between 8 and 14 years. PK RESULTS: Both median fibrinogen plasma antigen and activity levels reached a maximum within 30 minutes to 1 h post-infusion and decreased continuously afterwards. Median fibrinogen plasma activity levels were at or close to the limit of detection by Day 10 post-infusion. PK findings were similar for fibrinogen activity and antigen. Median Cmax and AUC were 1.3 g/L and 126.8 hours*mg/mL, with a median t1/2 of 77.1 hours for fibrinogen activity. For fibrinogen antigen, median Cmax and AUC were 1.3 g/L and 122.4 hours*mg/mL, with a median t1/2 of 88.0 hours. Whereas no statistically relevant effect of gender was seen on the PK parameters for fibrinogen activity, subjects &lt;16 years old (N=4) had higher median Vss, and Cl values and lower median t1/2, AUC, and MRT values than older subjects (N=10). The median incremental IVR was 1.7 mg/dL increase per mg/kg body weight. for fibrinogen activity and antigen. EFFICACY: The mean change in MCF between pre-infusion and 1 hour post-infusion was (8.9 mm) (p&lt;0.0001). A secondary analysis performed as a sensitivity analysis in the ITT population confirmed this result (mean change of 10.3 mm; p&lt;0.0001). Mean change from pre-infusion to 1 hour post-infusion was similar for subjects &lt;16 years of age (9.9 mm; N=4) and subjects ≥16 to &lt;65 years of age (8.5 mm; N=10) as well as for males (9.0 mm; N=9) and females (8.8 mm; N=5). SAFETY: Four adverse events from two patients were reported. All were mild, non-serious and assessed by the investigators as not related to study medication. CONCLUSION: The PK results for this study of a plasma-derived fibrinogen concentrate showed a sufficient and rapid increase in fibrinogen plasma level and a long half-life. The study demonstrated a significant increase in MCF as a surrogate efficacy parameter and a good safety profile for fibrinogen concentrate in patients with afibrinogenemia.

scholarly journals Epidemiological Effect of Gene Deployment Strategies on Bacterial Blight of Rice

1997 ◽  
Vol 87 (1) ◽  
pp. 66-70 ◽  
Author(s):  
Hafiz U. Ahmed ◽  
Maria R. Finckh ◽  
Rizal F. Alfonso ◽  
Christopher C. Mundt
Keyword(s):  
Resistance Genes ◽  
Partial Resistance ◽  
Bacterial Blight ◽  
Blight Resistance ◽  
Resistant Line ◽  
Bacterial Blight Resistance ◽  
Progress Curve ◽  
Two Component ◽  
The Mean ◽  
Bacterial Blight Of Rice

Experiments were conducted in farmers' fields at two locations of the irrigated lowlands of Laguna province in southern Luzon island, Philippines, during the wet seasons of 1993 and 1994. Nine rice populations were studied including pure stands, two-component mixtures, two-gene combinations of backcrossed lines containing varying combinations of the bacterial blight resistance genes Xa-4, xa-5, and Xa-10, and a non-isogenic cultivar containing Xa-4 and partial resistance to bacterial blight. The area under the disease progress curve (AUDPC) of both gene combinations studied was significantly less than the single most effective gene of each combination deployed singly. A mixture of a susceptible and a resistant line expressed an AUDPC significantly less than the mean of its component pure stands, but two other mixtures did not. The cultivar IR20, which contains both Xa-4 and partial resistance, reduced the AUDPC by about two-thirds as compared with IR-BB4, which contains Xa-4 and little or no partial resistance.

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