scholarly journals Simplification of a haemolytic micromethod for toxic saponin quantification in alfalfa

2013 ◽  
Vol 41 (2) ◽  
pp. 315-319 ◽  
Author(s):  
Piotr M. Górski ◽  
Marian Jurzysta
Keyword(s):  
Plant Material ◽  
Sample Weight ◽  
Modified Method ◽  
Large Numbers ◽  
Good Agreement ◽  
Sample Quantification

A simplification of a haemolytic micromethod is presented. In the orginal method, alfalfa (<i>Medicago media</i> Pers.) leaf sap is spotted on the plate covered with a blood-gelatine suspension. In the presented method, the mashed alfalfa pulp is used instead of sap. Due to saponin diffusion and the reaction with erythrocytes, a haemolytic ring appears, which has a width proportional to the concentration of toxic saponins. It is shown that the width of haemolytic ring does not depend on the sample weight ranging from 20 to 100 mg. This allows for the omission of laborious sap pressing and sample quantification. Individual alfalfa plants with different saponin contents were tested using leaf sap and leaf pulp for analyses. Good agreement was found with sap and leaf pulp methods. The correlation obtained by both methods was high, <i>r</i> = 0.87. The modified method requires only a small amount of plant material and makes the analyses of large numbers of individual plants per day possible. The method is especially recommended for breeding purposes.

Quantitative Determination of Carbon in Solid Hydrocarbons Using the Intensity Ratio of Incoherent to Coherent Scattering of X-Rays

1964 ◽  
Vol 18 (6) ◽  
pp. 171-174 ◽  
Author(s):  
C. J. Toussaint ◽  
G. Vos
Keyword(s):  
Intensity Ratio ◽  
Coherent Scattering ◽  
X Rays ◽  
Ray Method ◽  
Sample Weight ◽  
X Ray ◽  
Carbon Determination ◽  
Solid Hydrocarbons ◽  
Good Agreement

A method is presented for the determination of carbon in solid hydrocarbons using the intensity ratio of incoherent to coherent scattering of x-rays. The method is very rapid with precision at the 95% confidence level of about ±0.3%. The minimum sample weight necessary is 0 2 g. Analysis of samples by the x-ray method shows good agreement with values obtained by microcombustion. Finally a general comparison between different methods for carbon determination in solid hydrocarbons is discussed.

scholarly journals Initial Model for the Impact of Social Distancing on CoVID-19 Spread

2020 ◽  
Author(s):  
Genghmun Eng
Keyword(s):  
Exponential Growth ◽  
Growth Function ◽  
Worst Case ◽  
Social Distancing ◽  
Sick People ◽  
Large Numbers ◽  
The World ◽  
The Usa ◽  
The Impact ◽  
Good Agreement

AbstractThe initial stages of the CoVID-19 coronavirus pandemic all around the world exhibit a nearly exponential rise in the number of infections with time. Planners, governments, and agencies are scrambling to figure out “How much? How bad?” and how to effectively treat the potentially large numbers of simultaneously sick people. Modeling the CoVID-19 pandemic using an exponential rise implicitly assumes a nearly unlimited population of uninfected persons (“dilute pandemic”). Once a significant fraction of the population is infected (“saturated pandemic”), an exponential growth no longer applies. A new model is developed here, which modifies the standard exponential growth function to account for factors such as Social Distancing. A Social Mitigation Parameter [SMP] αS is introduced to account for these types of society-wide changes, which can modify the standard exponential growth function, as follows: The doubling-time tdbl = (In 2)/Ko can also be used to substitute for Ko, giving a {tdbl, αS} parameter pair for comparing to actual CoVID-19 data. This model shows how the number of CoVID-19 infections can self-limit before reaching a saturated pandemic level. It also provides estimates for: (a) the timing of the pandemic peak, (b) the maximum number of new daily cases that would be expected, and (c) the expected total number of CoVID-19 cases. This model shows fairly good agreement with the presently available CoVID-19 pandemic data for several individual States, and the for the USA as a whole (6 Figures), as well as for various countries around the World (9 Figures). An augmented model with two Mitigation Parameters, αS and βS, is also developed, which can give better agreement with the daily new CoVID-19 data. Data-to-model comparisons also indicate that using αS by itself likely provides a worst-case estimate, while using both αS and βS likely provides a best-case estimate for the CoVID-19 spread.

Initial Model for Impact of Social Distancing on CoVID-19 Spread (Preprint)

2020 ◽  
Author(s):  
Genghmun Eng
Keyword(s):  
Exponential Growth ◽  
Growth Function ◽  
Worst Case ◽  
Social Distancing ◽  
Sick People ◽  
S Parameter ◽  
Large Numbers ◽  
The World ◽  
The Usa ◽  
Good Agreement

UNSTRUCTURED The initial stages of the CoVID-19 coronavirus pandemic all around the world exhibit a nearly exponential rise in the number of infections with time. Planners, governments, and agencies are scrambling to figure out "How much? How bad?" and how to effectively treat the potentially large numbers of simultaneously sick people. Modeling the CoVID-19 pandemic using an exponential rise implicitly assumes a nearly unlimited population of uninfected persons ("dilute pandemic"). Once a significant fraction of the population is infected ("saturated pandemic"), an exponential growth no longer applies. A new model is developed here, which modifies the standard exponential growth function to account for factors such as Social Distancing. A Social Mitigation Parameter [SMP] α/s\ is introduced to account for these types of society-wide changes, which can modify the standard exponential growth function, as follows: N(t)= No exp[ +Ko t/(1 + α/s\ t)] . The doubling-time t/dbl\=(ln2)/Ko can also be used to substitute for Ko, giving a {t/dbl\, α/s\} parameter pair for comparing to actual CoVID-19 data. This model shows how the number of CoVID-19 infections can self-limit before reaching a saturated pandemic level. It also provides estimates for: (a) the timing of the pandemic peak, (b) the maximum number of new daily cases that would be expected, and (c) the expected total number of CoVID-19 cases. This model shows fairly good agreement with the presently available CoVID-19 pandemic data for several individual States, and the for the USA as a whole (6 Figures), as well as for various countries around the World (9 Figures). An augmented model with two Mitigation Parameters, α/s\ and β/s\, is also developed, which can give better agreement with the daily new CoVID-19 data. Data-to-model comparisons also indicate that using α/s\ by itself likely provides a worst-case estimate, while using both α/s\ and β/s\ likely provides a best-case estimate for the CoVID-19 spread.

scholarly journals THE CHEMISTRY OF DAYLIGHT VISION

1946 ◽  
Vol 29 (5) ◽  
pp. 277-297 ◽  
Author(s):  
Alfred Frederick Bliss
Keyword(s):  
Magnesium Sulfate ◽  
Inorganic Phosphate ◽  
Chemical Properties ◽  
Partial Purification ◽  
First Order ◽  
Large Numbers ◽  
Cone Cells ◽  
Polar Organic Solvents ◽  
Color Filters ◽  
Good Agreement

1. While several reports of photosensitive pigments from the retinas of animals possessing large numbers of cone cells have been published, the only study which could be confirmed was Wald's discovery of iodopsin, a red-sensitive pigment from chicken eyes. 2. In its chemical properties, such as the range of pH stability and the effect of polar organic solvents, iodopsin resembles rhodopsin but is considerably more labile. 3. A partial purification from inert yellow impurities has been effected by prehardening the retinas in pH 4.9 acetate buffer before extraction by 2 per cent digitonin. Rhodopsin was an inevitable contaminant in most methods of extraction, but could be reduced to about 10 per cent of the absorption due to iodopsin by extraction of unhardened retinas with 4 per cent Merck's saponin in ¾ saturated magnesium sulfate for about 1 hour. 4. The rate of bleaching of iodopsin was found to be first order and linear with respect to energy. 5. The bleaching effectiveness spectrum of iodopsin was determined with the aid of color filters of known energy transmission, and shows a maximum at 560 mµ in the yellow green with a lower plateau in the blue. The spectrum is in good agreement with the sensitivity of the human cones except for the wavelength of maximum bleaching effectiveness. The maximum sensitivity of the human cones is found at 540 mµ. 6. Previous reports of changes in pH and inorganic phosphate level of retinas due to bleaching could not be confirmed.

Micropropagation of Deschampsia antarctica - a frost-resistant Antarctic plant

2005 ◽  
Vol 17 (1) ◽  
pp. 69-70 ◽  
Author(s):  
MARELY CUBA ◽  
ANA GUTIÉRREZ-MORAGA ◽  
BARBARA BUTENDIECK ◽  
MANUEL GIDEKEL
Keyword(s):  
Tissue Culture ◽  
Antarctic Peninsula ◽  
Plant Material ◽  
Deschampsia Antarctica ◽  
Culture Methods ◽  
Large Numbers ◽  
Micro Propagation ◽  
Self Fertilization ◽  
Harsh Climate ◽  
The Antarctic

Deschampsia antarctica Desv. (Poaceae) is the only native Gramineae found in the Antarctic, where it is restricted to the Antarctic Peninsula and its offshore islands. Its ability to survive the harsh climate has attracted the interest of scientists searching for genes associated with freezing tolerance (Alberdi et al. 2002). For continuing research purposes it would be better if plants did not have to be collected from the field, but could be propagated effectively to provide the necessary experimental material D. antarctica normally reproduces both by seed produced by self-fertilization and also vegetatively from tillers (Holderegger et al. 2003). Vegetative propagation is slow and unable to generate enough plant material for laboratory requirements. This difficulty prompted us to develop a rapid micro-propagation method using tissue-culture methods for the production of large numbers of plants in relatively short periods.

Comparative Study on Deflection Calculation for Concrete Flexural Members with Fiber Reinforced Polymer Reinforcement

2011 ◽  
Vol 183-185 ◽  
pp. 1979-1983
Author(s):  
Jiang Yong Cai ◽  
Xi Bo Zhou ◽  
Xiong Jia ◽  
Yan Tao He
Keyword(s):  
Concrete Beams ◽  
Reinforce Concrete ◽  
Fiber Reinforced Polymer ◽  
New Method ◽  
Flexural Members ◽  
Modified Method ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Frp Bars ◽  
Good Agreement

The application and development of FRP bars for reinforce concrete structures necessitates the need for either adopt the current code method or exploiting a new design one to account for the properties of FRP materials. The method for predicting deflection of concrete beams with FRP bars in ACI440 is based on the method for that with steel bars in ACI318. Similarly, a modified method based on GB50010 is proposed in this paper to estimate deflection of concrete beams with FRP bars. Furthermore, the new method, together with ACI318, ACI440 and GB50010 ones, are verified by nine test beams in three existing experiment and show a good agreement with the experimental data. Simultaneously, the new method is also proved to be of the most precise and accurate one and indicates the potential of the method to estimate deflection in Chinese code system.

Direct ingestion of plant sap from cut leaves by the leaf-cutting ants Atta cephalotes (L.) and acromyrmex octospinosus (reich) (Formicidae, Attini)

1976 ◽  
Vol 66 (2) ◽  
pp. 205-217 ◽  
Author(s):  
M. Littledyke ◽  
J. M. Cherrett
Keyword(s):  
Plant Material ◽  
Atta Cephalotes ◽  
Fungus Garden ◽  
Acromyrmex Octospinosus ◽  
Substrate Preparation ◽  
Fungus Culture ◽  
Large Numbers ◽  
Leaf Cutting ◽  
Laboratory Colonies ◽  
Reduced Drinking

AbstractIngestion of radiolabelled plant juices from cut surfaces of leaves during foraging and during substrate preparation for the fungus garden was demonstrated for laboratory colonies of the leaf-cutting ants Atta cephalotes (L.) and Acromyrmex octospinosus (Reich). Using P32 isotope, up to one-third of the radioactivity in the leaves was taken in directly by the colony as a whole, but this was much less when C14 was used. Additional plant material was taken in by the ants via the fungus garden. Large numbers of ants spend time in investigating cut surfaces of leaves and also in cutting and crimping leaves. Ingestion of plant material during these processes could play an important nutritional role in the colony and this may explain why many ants return from foraging apparently unladen. Large ants obtained most of their plant juice intake during foraging and the medium and small ants took much of theirs during substrate preparation. Inhibitory chemicals did not affect cutting but they reduced drinking and also reduced the intake of P32 from leaves during substrate preparation. The ants also ingested different amounts of P32 from leaves of different acceptability. It is suggested that leaf-cutting ants use fungus culture as a means of ‘sidestepping’ plant inhibitors. Nutrients are ingested directly from leaves when these are palatable, and the less palatable components are made available to the ants via the fungus.

scholarly journals Striking heterogeneity of somatic L1 retrotransposition in single normal and cancerous gastrointestinal cells

2020 ◽  
Vol 117 (51) ◽  
pp. 32215-32222 ◽  
Author(s):  
Katsumi Yamaguchi ◽  
Alisha O. Soares ◽  
Loyal A. Goff ◽  
Anjali Talasila ◽  
Jungbin A. Choi ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Tumor Cells ◽  
Single Cell Analysis ◽  
Single Cells ◽  
Variable Number ◽  
Normal Tissues ◽  
Modified Method ◽  
Cellular Environment ◽  
Large Numbers ◽  
Cancer Tissues

Somatic LINE-1 (L1) retrotransposition has been detected in early embryos, adult brains, and the gastrointestinal (GI) tract, and many cancers, including epithelial GI tumors. We previously found numerous somatic L1 insertions in paired normal and GI cancerous tissues. Here, using a modified method of single-cell analysis for somatic L1 insertions, we studied adenocarcinomas of colon, pancreas, and stomach, and found a variable number of somatic L1 insertions in tumors of the same type from patient to patient. We detected no somatic L1 insertions in single cells of 5 of 10 tumors studied. In three tumors, aneuploid cells were detected by FACS. In one pancreatic tumor, there were many more L1 insertions in aneuploid than in euploid tumor cells. In one gastric cancer, both aneuploid and euploid cells contained large numbers of likely clonal insertions. However, in a second gastric cancer with aneuploid cells, no somatic L1 insertions were found. We suggest that when the cellular environment is favorable to retrotransposition, aneuploidy predisposes tumor cells to L1 insertions, and retrotransposition may occur at the transition from euploidy to aneuploidy. Seventeen percent of insertions were also present in normal cells, similar to findings in genomic DNA from normal tissues of GI tumor patients. We provide evidence that: 1) The number of L1 insertions in tumors of the same type is highly variable, 2) most somatic L1 insertions in GI cancer tissues are absent from normal tissues, and 3) under certain conditions, somatic L1 retrotransposition exhibits a propensity for occurring in aneuploid cells.

Pseudomonas mors-prunorum. [Descriptions of Fungi and Bacteria].

1967 ◽  
Author(s):  
J. F. Bradbury
Keyword(s):  
Great Britain ◽  
Geographical Distribution ◽  
Leaf Spot ◽  
Seasonal Cycle ◽  
Plant Material ◽  
Early Summer ◽  
Bacterial Canker ◽  
Stone Fruits ◽  
Large Numbers ◽  
Young Leaves

Abstract A description is provided for Pseudomonas mors-prunorum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Prunus spp. especially plum and cherry. DISEASE: Bacterial canker, leaf spot and shoot wilt of stone wits. A definite seasonal cycle occurs in which a winter canker alternates with a summer leaf spot (Crosse, 1954). The symptoms are indistinguishable from those caused by P. syringae on stone fruits. GEOGRAPHICAL DISTRIBUTION: Mainly in Europe, where it has been reported from Denmark, Finland, France, Germany, Great Britain, Greece, Ireland, Netherlands, Switzerland, Rumania, U.S.S.R. (Ukraine), Yugoslavia and, recently, (46, 381) from Italy. Also in Australia (N.S.W.) and Canada (N.S.). (CMI Map 132, Ed. 2, 1966). TRANSMISSION: The pathogen is probably introduced into new orchards most frequently on plant material, where infected spurs may show such slight symptoms as to pass unnoticed (Crosse, 1954). The pathogen is spread locally by wind and rain. In early summer young leaves can be invaded but stems become difficult or impossible to infect at this time. As the leaves mature they lose their susceptibility and large numbers of bacteria are found on their surfaces. These bacteria are carried by rain to infect the branches, which are again susceptible in the autumn, through wounds and incompletely healed leaf scars. This autumn infection leads to the canker phase that develops slowly through the winter and in the spring causes infection of the new leaves as they expand. In summer the bacteria in the cankers die out. The cankers are not, therefore, perennial, but are readily reinfected in the autumn.

Dynamic Stability and Natural Frequency of Composite Corrugated Bellow Expansion Joint

2013 ◽  
Author(s):  
SujanaRao Nakkanti ◽  
Radhakrishna Madabhushi ◽  
MuraliKrishnaPrasad Adusumilli
Keyword(s):  
Natural Frequency ◽  
Integration Method ◽  
Torsional Stiffness ◽  
The Finite Element Method ◽  
Expansion Joint ◽  
Modified Method ◽  
Pipe Model ◽  
Thin Walled Pipe ◽  
Torsional Frequency ◽  
Good Agreement

The paper deals with torsional stiffness and natural frequency of composite corrugated bellows type of expansion joint. In this paper simplified formulae are developed considering thin walled pipe model. Integration method is used to determine the natural frequency of bellows. The EJMA {1} method of calculating the torsional frequency is modified using two different equivalent radii. The results obtained by the modified method are compared with the finite element method and found to be in good agreement.

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