Response of plant species to concentrations of zinc in solution. I. Growth and zinc content of plants

1968 ◽  
Vol 19 (6) ◽  
pp. 859 ◽  
Author(s):  
MD Carroll ◽  
JF Loneragan
Keyword(s):  
Plant Species ◽  
Zinc Content ◽  
Culture Method ◽  
Yield Response ◽  
Good Growth ◽  
Nutrient Culture ◽  
Soil Solutions ◽  
Standard Culture ◽  
Zinc Concentrations ◽  
Toxicity Effects

When eight plant species were grown in a flowing culture system over a range of constant zinc concentrations, all species produced maximum yields at concentrations of zinc in solution below those usually considered adequate for plant growth. All species made good growth at a concentration of 0.01 µM zinc and maximal growth at 0.25 µM zinc or less. Toxicity effects were also induced at lower concentrations (1–6 µM) than previously reported. Differences in yield response among species did not agree in all cases with previously reported responses in standard culture and in the field. Disagreement between results in the flowing culture method used here and the standard methods of nutrient culture may arise from the contrasting characteristics of zinc supply under which deficiency develops. It is considered that results from both methods have relevance to the absorption of zinc by plants from soil solutions.

Response of plant species to concentrations of zinc in solution. II. Rates of zinc absorption and their relation to growth

1969 ◽  
Vol 20 (3) ◽  
pp. 457 ◽  
Author(s):  
MD Carroll ◽  
JF Loneragan
Keyword(s):  
Plant Species ◽  
Zinc Deficiency ◽  
Zinc Concentration ◽  
Zinc Absorption ◽  
Maximal Growth ◽  
Standard Culture ◽  
Rate Of Absorption ◽  
Zinc Concentrations ◽  
The Relationship

Rates of zinc absorption by eight plant species grown for 46 days increased almost linearly from 2 to 400 ng atoms Zn/g fresh roots/day as zinc concentration in flowing culture solutions increased from 0.01 to 6.25µM At particular zinc concentrations, rates of absorption were about one-tenth of those reported for excised roots and up to 50 times greater than calculated rates of absorption from standard culture solutions. Reasons for these discrepancies arc discussed. At rates of zinc absorption of 2–4 ng atoms/g fresh roots/day many species developed symptoms of zinc deficiency and no species made maximal growth. Increasing rates of absorption to 10 ng atoms/g/day increased the growth of all species to maximal or near-maximal growth. Increasing rates of absorption beyond this slightly increased the yield of some species, but between 20 and 100 ng atoms/g/day there was no effect on the yield of any species. Rates in excess of 240 ng atoms/g/day were associated with depressed yields in all legumes but not in any cereals. Differences in rates of zinc absorption contributed to, but could not solely account for, differences among species in response to zinc concentrations in solution. The extent to which other factors may have modified the relationship between rate of absorption and yield is discussed.

scholarly journals Evaluation of StrepBSelectChromogenic Medium and the Fast-Track Diagnostics Group B Streptococcus (GBS) Real-Time PCR Assay Compared to Routine Culture for Detection of GBS during Antepartum Screening

2017 ◽  
Vol 55 (7) ◽  
pp. 2137-2142 ◽  
Author(s):  
Deirdre L. Church ◽  
Heather Baxter ◽  
Tracie Lloyd ◽  
Oscar Larios ◽  
Daniel B. Gregson
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Fast Track ◽  
Group B Streptococcus ◽  
Culture Method ◽  
Predictive Values ◽  
Content Type ◽  
Standard Culture ◽  
Group B ◽  
The Cost

ABSTRACTLife-threatening infection in neonates due to group BStreptococcus(GBS) is preventable by screening of near-term pregnant women and treatment at delivery. A total of 295 vaginal-rectal swabs were collected from women attending antepartum clinics in Calgary, Alberta, Canada. GBS colonization was detected by the standard culture method (Strep B Carrot Broth subcultured to blood agar with a neomycin disk) and compared to recovery with Strep Group B Broth (Dalynn Biologicals) subcultured to StrepBSelectchromogenic medium (CM; Bio-Rad Laboratories) and the Fast-Track Diagnostics GBS real-time PCR (quantitative PCR [qPCR]) assay (Phoenix Airmid Biomedical Corp.) performed with broth-enriched samples and the Abbottm2000sp/m2000rt system. A total of 62/295 (21%) women were colonized with GBS; 58 (19.7%) cases were detected by standard culture, while CM and qPCR each found 61 (20.7%) cases. The qPCR and CM were similar in performance, with sensitivities, specificities, and positive and negative predictive values of 98.4 and 98.4%, 99.6 and 99.6%, 98.4 and 98.4%, and 99.6 and 99.6%, respectively, compared to routine culture. Both qPCR and CM would allow more rapid reporting of routine GBS screening results than standard culture. Although the cost per test was similar for standard culture and CM, the routine use of qPCR would cost approximately four times as much as culture-based detection. Laboratories worldwide should consider implementing one of the newer methods for primary GBS testing, depending on the cost limitations of different health care jurisdictions.

The Effect of Synchronous Moulting on Body Copper and Zinc Concentrations in Four Species of Talitrid Amphipods (Crustacea)

1991 ◽  
Vol 71 (2) ◽  
pp. 481-488 ◽  
Author(s):  
J. M. Weeks ◽  
P. G. Moore
Keyword(s):  
Tidal Cycle ◽  
Zinc Content ◽  
Lunar Cycle ◽  
Moult Cycle ◽  
Metal Concentrations ◽  
Total Copper ◽  
Copper And Zinc ◽  
Talitrus Saltator ◽  
Zinc Concentrations ◽  
New Moon

Analysis of the total copper and zinc content of four species of talitrid amphipods, Orchestia gammarellus, O. mediterranea, Talitrus saltator and Talorchestia deshayesii throughout a complete spring/neap tidal cycle failed to reveal any significant effects of moulting upon body copper or zinc in any species. Moulting was synchronized to the lunar cycle only in T. saltator, taking place 5–7 days prior to a new moon. The fact that no significant changes in body metal concentrations took place with the moult cycle is discussed in relation to the use of talitrid amphipods in copper and zinc biomonitoring programmes.

scholarly journals Assessment of Various Laboratory Diagnostic Methods in Diagnosis of Cutaneous Tuberculosis. A Study from A Tertiary Care Hospital of North India

2021 ◽  
Author(s):  
Shoaib Khan ◽  
Nahid Nahvi ◽  
Umara Amin ◽  
Yousuf Ul Bashir ◽  
Danish Zahoor
Keyword(s):  
Tertiary Care ◽  
Culture Method ◽  
Diagnostic Methods ◽  
North India ◽  
Care Hospital ◽  
Age Group ◽  
Cutaneous Tuberculosis ◽  
Standard Culture ◽  
Lowenstein Jensen ◽  
Culture Positive

Cutaneous tuberculosis (CTB) is the rarest case of extrapulmonary TB comprising 2% of total cases. It’s often a challenge both clinically and diagnostically. 1) To determine prevalence, age & gender-wise distribution of CTB. 2) To assess various diagnostic, microbiological modalities for the diagnosis of CTB. 76 skin biopsy specimens from suspected CTB lesions were analysed using following methods – Acid-fast Bacilli (AFB) staining (Ziehl-Neelsen method), growth of mycobacteria in culture (Lowenstein-Jensen media), and Gene Xpert MTB/RIF, Histopathological (H&E staining). Of the 76 specimens, 44 were males and 32 were females. The most commonly affected age group was 40–59 years. Infections were least common in 0-19 years age group. AFB was not seen in any of the primary smears. 10 were confirmed as CTB by the recovery of Mycobacterium in solid culture. Of the 10 culture positives, 9 were confirmed as MTB, and 1 was found to be NTM. Staining of 10 culture positive specimens revealed acid fast, beaded rods. Detection of MTB by Gene Xpert gave positive result in 9 cases with all RIF sensitive. All 9 PCR confirmed cases were also culture positive, all 9 were slow growers with a minimum of 5 weeks required for growth on the LJ slant. PCR is the test of choice and should be performed on all specimens of suspected CTB. However when coupled with the “gold standard” culture method, the diagnostic accuracy improves. Also, further, culture helps in identification and isolation of NTM’s.

Changes in plasma zinc content after exercise in men fed a low-zinc diet

1984 ◽  
Vol 247 (1) ◽  
pp. E88-E93 ◽  
Author(s):  
H. C. Lukaski ◽  
W. W. Bolonchuk ◽  
L. M. Klevay ◽  
D. B. Milne ◽  
H. H. Sandstead
Keyword(s):  
Copper Content ◽  
Maximal Exercise ◽  
Strong Predictor ◽  
Zinc Content ◽  
Plasma Zinc ◽  
Zinc Depletion ◽  
Plasma Copper ◽  
Zinc Concentrations ◽  
Zinc Repletion ◽  
Zinc Balance

For 30 days five healthy men aged 23-57 yr consumed a diet adequate in zinc (8.6 mg/day); they ate a low-zinc diet (3.6 mg/day) for the next 120 days and then received a zinc-supplemented (33.6 mg/day) diet for 30 days. Copper intake was constant at 1.8 mg/day. Aerobic capacity was determined periodically during each diet period. Relative zinc balance (% of control) declined during depletion (r = -0.28, P less than 0.009). Pre- and postexercise zinc concentrations decreased when dietary zinc was restricted (r = -0.61, P less than 0.0001 and r = -0.78, P less than 0.0001) and increased with supplementation (r = 0.61, P less than 0.008 and r = 0.76, P less than 0.0003, respectively). Both plasma zinc and hematocrit increased (P less than 0.01) after maximal exercise. To minimize the effect of hemoconcentration during exercise, the van Beaumont quotient (J. Appl. Physiol. 34: 102-106, 1973) was calculated using pre- and postexercise hematocrit and plasma zinc. The initial quotient of 1.8 +/- 1.8% (mean +/- SE) declined (P less than 0.05) to -7.4 +/- 2.3% during depletion. With zinc repletion, the quotient increased to 6.9 +/- 3.6%, which was greater (P less than 0.05) than the quotient in depletion but similar to the initial quotient. The quotient was a strong predictor (r = 0.71, P less than 0.0005) of the change in relative zinc balance during zinc depletion. In contrast, no changes were found in plasma copper content. These data suggest that zinc mobilization from tissues is impaired during zinc depletion, and they validate the use of the van Beaumont quotient as an index of change in body zinc stores.

Comparison of Two Enzyme Immunoassays for Recovery of Salmonella spp. from Four Low-Moisture Foods

1992 ◽  
Vol 55 (8) ◽  
pp. 601-604 ◽  
Author(s):  
GERALDINE ALLEN JUNE ◽  
PATRICIA S. SHERROD ◽  
WALLACE H. ANDREWS
Keyword(s):  
False Negative ◽  
Culture Method ◽  
Lower Number ◽  
Salmonella Spp ◽  
False Negatives ◽  
Enzyme Immunoassays ◽  
Assay Result ◽  
Standard Culture ◽  
Low Moisture Foods ◽  
Number Of Cells

Two enzyme immunoassays (Salmonella-Tek™ and Report™) were compared with the standard culture method of the Association of Official Analytical Chemists (AOAC) and the Food and Drug Administration's Bacteriological Analytical Manual (BAM) for the recovery of Salmonella spp. from four low-moisture foods. Two protocols were used to compare the effectiveness of the two immunoassays: i) foods were contaminated in the dry state; or ii) serial tenfold dilutions of Salmonella spp. were inoculated into the postenrichments after incubation. Of three hundred 25-g test portions inoculated in the dry state, 199 gave confirmed positive reactions with the Salmonella-Tek™ assay, 193 with the Report™ assay, and 206 with the AOAC/BAM method. There were seven false-negative reactions with Salmonella-Tek™ and 13 false negatives with the Report™, a false negative being defined as one that was negative by the enzyme immunoassay but was confirmed positive by the AOAC/BAM culture method. When the postenrichments were inoculated after incubation, a lower number of cells gave a positive assay result with the Salmonella-Tek™ system than with the Report™ system, indicating greater sensitivity

scholarly journals Actinobacillus (Haemophilus) Pleuropneumoniae: Use of Coagglutination and Complement Fixation to Determine the Relationship between Presence of Organism and Antibody Titer in Slaughterhouse Pigs

1989 ◽  
Vol 1 (1) ◽  
pp. 12-15 ◽  
Author(s):  
Lorraine J. Hoffman
Keyword(s):  
Respiratory Disease ◽  
Complement Fixation ◽  
Culture Method ◽  
Respiratory Problems ◽  
Conventional Culture ◽  
Significant Difference ◽  
Positive Threshold ◽  
Standard Culture ◽  
History Of ◽  
The Difference

The conventional culture method was compared to coagglutination for detection of Actinobacillus (Haemophilus) pleuropneumoniae in 425 sets of pig lungs. Sera from the same animals were evaluated for antibodies to A. pleuropneumoniae by the complement fixation (CF) test. All samples were collected at 2 packing plants in Iowa. In 2 nonvaccinated herds with no history of respiratory disease, the difference between standard culture results and coagglutination was highly significant ( P < 0.001). None of the 57 pigs in this group were positive for A. pleuropneumoniae by conventional culture, but 7 were positive by the coagglutination test. There were 15 animals with CF titers between 1:8 and 1:32. Animals from 6 herds vaccinated for A. pleuropneumoniae and without recent respiratory problems were evaluated. One out of 118 animals tested was positive for A. pleuropneumoniae by standard culture as compared to 9 positive by coagglutination. The difference in positive results between culture and coagglutination was highly significant ( P < 0.001). Twenty-eight animals had CF titers to A. pleuropneumoniae (1:4 to ≥ 1: 128). Two hundred fifty lungs and sera samples were collected from 7 herds which had recently experienced varying degrees of respiratory disease. Thirty-nine lungs were positive for A. pleuropneumoniae by culture and 182 were positive by coagglutination. The number of positives detected by coagglutination was significantly different ( P < 0.001) from the number positive by culture. There were 172 animals with antibody titers ranging from suspect to ≥ 1:128. There were significantly fewer positive animals detected by standard culture than with the CF test ( P < 0.001). There was no significant difference between coagglutination results and CF titers when a titer of 1:4 was used as the positive threshold.

scholarly journals Evaluation of a two-minute strep A direct swab test (SADST) on patients with pharyngitis at a primary care clinic

1986 ◽  
Vol 97 (1) ◽  
pp. 133-138 ◽  
Author(s):  
G. F. Araj ◽  
H. A. Majeed
Keyword(s):  
Primary Care ◽  
Primary Care Clinic ◽  
Culture Method ◽  
Care Clinic ◽  
Predictive Values ◽  
Primary Care Clinics ◽  
Clinical Laboratories ◽  
Standard Culture ◽  
Group A ◽  
Lancefield Group

SUMMARYA two-minute strep A direct swab test (SADST) was used to detect the presence of Lancefield group A streptococci (GAS) from the throats of 207 patients with pharyngitis at a primary-care clinic. The results were compared with a standard culture method. Fifty-one specimens were positive and 156 specimens were negative for GAS by culture. The SADST had a sensitivity of 96% (49 of 51) and specificity of 98·7% (154 of 156). The predictive values of a positive and negative SADST, for GAS, were 96% and 98·7 % respectively. The SADST showed negative reactions with five specimens containing beta-haemotytic streptococci other than GAS and 34 known stock cultures other than GAS. Our results indicate that SADST is a rapid, simple, convenient and reliable test to use for diagnosis of GAS pharyngitis at primary care clinics, physicians' offices and clinical laboratories.

Detection of legionella bacteria in sewage by polymerase chain reaction and standard culture method

1995 ◽  
Vol 31 (5-6) ◽  
pp. 409-416 ◽  
Author(s):  
Bruce M. Roll ◽  
Roger S. Fujioka
Keyword(s):  
Polymerase Chain Reaction ◽  
Sewage Treatment ◽  
Culture Method ◽  
Chain Reaction ◽  
Standard Culture ◽  
Pontiac Fever ◽  
Legionella Species ◽  
Legionnaires Disease ◽  
The Subject ◽  
Polymerase Chain

Legionella bacteria are ubiquitous in environmental waters. Only a few species of Legionella , especially, L. pneumophila are pathogenic to humans and cause a sometimes fatal Legionnaires disease as well as a less fatal disease called Pontiac fever. The presence of Legionella in sewage and aerosolized sewage is the subject of this investigation because reuse of sewage may involve the exposure of people to aerosolization, the mode of transmission of Legionella bacteria. The objective of this study was to determine the prevalence of Legionella species and L. pneumophila in wastewater and their fate after various stages of treatment. The polymerase chain reaction (PCR) and standard culture method were utilized to detect Legionella species and L. pneumophila. PCR results indicated that Legionella species were present at levels &gt; 103 cells / ml during all phases of sewage treatment including chlorinated effluents. Culture results indicated levels at least one log lower than seen with PCR. Legionella species were also recovered from air samples collected from secondary aeration basins at levels &lt; 103 cells/ml. PCR was shown to be the most rapid and sensitive method for detecting Legionella in sewage.

scholarly journals VIDAS® Enzyme-Linked Immunofluorescent Assay for Detection of Listeria in Foods: Collaborative Study

2000 ◽  
Vol 83 (4) ◽  
pp. 903-918 ◽  
Author(s):  
Vidhya Gangar ◽  
Michael S Curiale ◽  
Armando D’Onorio ◽  
Ann Schultz ◽  
Ronald L Johnson ◽  
...  
Keyword(s):  
False Positive Rate ◽  
Collaborative Study ◽  
False Negative ◽  
Traditional Culture ◽  
Culture Method ◽  
Contamination Level ◽  
Culture Methods ◽  
Positive Rate ◽  
Standard Culture ◽  
Lis Method

Abstract The VIDAS LIS method and the traditional culture methods for detection of Listeria species in food were evaluated in a multilaboratory comparative study. The 6 foods tested were either naturally contaminated or inoculated with 3 different concentrations of Listeria. Results for each food and each contamination level with the VIDAS LIS method were as good as or better than those obtained with the traditional culture method. Of 1558 samples tested, 935 were positive: 839 by the VIDAS method and 809 by standard culture methods. Overall false negative rates were 10.3 and 13.5% for the VIDAS LIS and culture methods, respectively. The false positive rate for the VIDAS LIS assay was 1.4% based on 9 VIDAS LIS positive assays that did not confirm positive by isolation of Listeria. The agreement between the VIDAS LIS and culture methods for all samples tested was 86%.

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