scholarly journals A comparison of methods for the estimation of the proportion of microbial nitrogen in duodenal digesta, and of correction for microbial contamination in nylon bags incubated in the rumen of sheep

1984 ◽  
Vol 52 (2) ◽  
pp. 403-417 ◽  
Author(s):  
P. M. Kennedy ◽  
G. P. Hazlewood ◽  
L. P. Milligan
Keyword(s):  
Analytical Methods ◽  
Microbial Contamination ◽  
Rumen Fluid ◽  
Plant Residues ◽  
Differential Centrifugation ◽  
Reed Canary Grass ◽  
Microbial Nitrogen ◽  
Canary Grass ◽  
The Difference

1. Four sheep, each fitted with cannulas in the rumen and proximal duodenum, were given two diets (1390 g dry matter (DM)/d) consisting of lucerne (Medicago sutiva) pellets (24.2 g nitrogen/kg DM) plus pelleted reed canary grass (Phaluris arundinacea; 14.1 g N/kg DM) or chopped hay (11.8 g N/kg DM) at intervals of 2 h. Flow of duodenal digesta measured by reference to the markers51Cr-EDTA and103Ru-phenanthroline indicated a net gain of 5.8–7.5 g non-ammonia-N (NAN) between mouth and duodenum.2. The proportion of microbial N in duodenal digesta N was estimated using15N and35S incorporation into bacteria and digesta. Two methods of analysis for35S content, the Bird & Fountain (1970; B&F method) and the Mathers & Miller (1980; M&M method), were used. (15NH4)2S04and Na235S04were infused into the rumen for 3.5 d before and 4.0 d during sampling. A bacterial fraction was prepared from the fluid phases of sampled duodenal digesta and rumen contents by differential centrifugation. In addition, samples of ground canary grass and of lucerne were incubated in nylon bags in the rumen for 3–48 h during the infusion.3. Each of the35S analytical methods yielded similar values of35S content of isolated rumen or duodenal bacteria, but there was more (P< 0.05) incorporation of15N into rumen than into duodenal bacteria. Relative to values obtained using the M&M method and15N incorporation, the B&F method for S analysis yielded higher (P< 0.05) estimates of microbial content of duodenal digesta from sheep given chopped reed canary grass.4.35S activity associated with washed nylon-bag residues increased rapidly with time-period of incubation and was substantially greater (P< 0.05) when analysed by the B&F method compared with the M&M method. The35S content (/g DM) of adherent bacteria removed from nylon-bag residues by homogenization in a second experiment vaned from 0.65 to 1.88 that of free-living bacteria isolated from rumen fluid by differential centrifugation.5. The difference in35S content in digesta and nylon-bag residues as measured using the two analytical methods was considered in relation to35S-labelled extracellular material postulated to be produced by bacteria adherent to plant residues. Estimates of disappearance of dietary N from nylon bags after correction for microbial contamination indicated a disparity with estimates based on in vivo information.

EFFECTS OF SELECTED REED CANARY GRASS ALKALOIDS ON IN VITRO DIGESTIBILITY

1977 ◽  
Vol 57 (3) ◽  
pp. 779-785 ◽  
Author(s):  
B. E. COULMAN ◽  
K. W. CLARK ◽  
D. L. WOODS
Keyword(s):  
Rumen Fluid ◽  
In Vitro Digestion ◽  
In Vitro Digestibility ◽  
Reed Canary Grass ◽  
Powdered Cellulose ◽  
Similar Work ◽  
Wide Range ◽  
Canary Grass ◽  
Rumen Microflora

A range of concentrations of pure samples of the alkaloids, gramine, hordenine, 5-methoxy-dimethyl tryptamine and N-methyl tryptamine which are normal constituents of reed canary grass were added to in vitro rumen fluid fermentations. Powdered cellulose and ground reed canary grass were used as substrates and fermentation periods were 24 and 48 h. No consistent relationship was found between the concentration of any of the above alkaloids and in vitro digestion values for either of the substrates or fermentation periods. In other studies, 24- and 48-h in vitro digestions were carried out on reed canary grass clones harvested at early heading and 6-wk regrowth. These clones showed a very wide range of gramine, hordenine and total alkaloid levels. No relationship was found between the concentration and type of alkaloids in the clones and their in vitro digestibility. These findings are in keeping with earlier similar work and it was concluded that reported poor animal performance with reed canary grass is probably due to factors other than alkaloid interference with the rumen microflora.

Enhancement of ADP-induced Platelet Aggregation by Adrenaline in Vivo and Its Prevention

1973 ◽  
Vol 29 (02) ◽  
pp. 490-498 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Itsuro Kobayashi ◽  
Tadahiro Sano ◽  
Takio Shimamoto
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
The Other ◽  
Endothelial Surface ◽  
Important Interaction ◽  
Blood Coagulability ◽  
The Difference

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.

Reliability of a Single β-Thromboglobulin Measurement in a Diabetic Population : Importance of PGE1 in Anticoagulant Mixture

1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner
Keyword(s):  
In Vitro Release ◽  
Mean Value ◽  
Reliable Estimate ◽  
Diabetic Patients ◽  
Single Measurement ◽  
Diabetic Population ◽  
The Difference ◽  
Vitro Release

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.

Bare soil and reed canary grass ecosystem respiration in peat extraction sites in Eastern Finland

Tellus B ◽  
2008 ◽  
Vol 60 (2) ◽  
Author(s):  
N. J. Shurpali ◽  
N. P. Hyvönen ◽  
J. T. Huttunen ◽  
C. Biasi ◽  
H. Nykänen ◽  
...  
Keyword(s):  
Ecosystem Respiration ◽  
Bare Soil ◽  
Reed Canary Grass ◽  
Peat Extraction ◽  
Canary Grass ◽  
Eastern Finland

Mathematical models of Gauss – Kruger projection for calculation of meridians conversion on the plane and scale of the image

2018 ◽  
Vol 934 (4) ◽  
pp. 2-7
Author(s):  
P.A. Medvedev ◽  
M.V. Novgorodskaya
Keyword(s):  
Mathematical Models ◽  
Analytical Methods ◽  
Theoretical Studies ◽  
Spherical Trigonometry ◽  
Cylindrical Projection ◽  
Rectangular Coordinates ◽  
In Series ◽  
Observational Errors ◽  
The Difference

This work contains continued research carried out on improving mathematical models of the Gauss-Krueger projection in accordance with the parameters of any ellipsoid with the removal of points from the axial meridian to l ≤ 6° . In terms of formulae earlier derived by the authors with improved convergence for the calculation of planar rectangular coordinates by geodesic coordinates, the algorithms for determining the convergence of meridians on the plane and the scale of the image are obtained. The improvement of the formulae represented in the form of series in powers of the difference in longitudes was accomplished by separating spherical terms in series and then replacing their approximate sums by exact expressions using the formulae of spherical trigonometry. As in previous works published in this journal [7, 8], determining the sums of the spherical terms was carried out according to the laws of the transverse-cylindrical projection of the sphere on the plane. Theoretical studies are given and formulae are proposed for estimating the observational errors in the results of the derived algorithms. The maximum of observational errors of convergence of meridians and scale, proceeding from the specified accuracy of the determined quantities was established through analytical methods.

scholarly journals Force Generation on the Hallux Is More Affected by the Ankle Joint Angle than the Lesser Toes: An In Vivo Human Study

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 48
Author(s):  
Junya Saeki ◽  
Soichiro Iwanuma ◽  
Suguru Torii
Keyword(s):  
Repeated Measures ◽  
Joint Angle ◽  
Plantar Flexion ◽  
Human Study ◽  
Force Generation ◽  
Functional Difference ◽  
Multiple Comparison Test ◽  
The Difference ◽  
Metatarsophalangeal Joints

The structure of the first toe is independent of that of the other toes, while the functional difference remains unclear. The purpose of this study was to investigate the difference in the force generation characteristics between the plantar-flexion of the first and second–fifth metatarsophalangeal joints (MTPJs) by comparing the maximal voluntary plantar-flexion torques (MVC torque) at different MTPJs and ankle positions. The MVC torques of the first and second–fifth MTPJs were measured at 0°, 15°, 30°, and 45° dorsiflexed positions of the MTPJs, and at 20° plantar-flexed, neutral, and 20° dorsiflexed positions of the ankle. Two-way repeated measures analyses of variance with Holm’s multiple comparison test (MTPJ position × ankle position) were performed. When the MTPJ was dorsiflexed at 0°, 15°, and 30°, the MVC torque of the first MTPJ when the ankle was dorsiflexed at 20° was higher than that when the ankle was plantar-flexed at 20°. However, the ankle position had no significant effect on the MVC torque of the second–fifth MTPJ. Thus, the MVC torque of the first MTPJ was more affected by the ankle position than the second–fifth MTPJs.

scholarly journals Reaction of Chalcones with Cellular Thiols. The Effect of the 4-Substitution of Chalcones and Protonation State of the Thiols on the Addition Process. Diastereoselective Thiol Addition

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4332
Author(s):  
Fatemeh Kenari ◽  
Szilárd Molnár ◽  
Pál Perjési
Keyword(s):  
Biological Effects ◽  
Equilibrium Composition ◽  
Deprotonated Form ◽  
Degree Of Ionization ◽  
Thiol Reactivity ◽  
Michael Type Addition ◽  
Ph Conditions ◽  
The Difference ◽  
Initial Reactivity

Several biological effects of chalcones have been reported to be associated with their thiol reactivity. In vivo, the reactions can result in the formation of small-molecule or protein thiol adducts. Both types of reactions can play a role in the biological effects of this class of compounds. Progress of the reaction of 4-methyl- and 4-methoxychalcone with glutathione and N-acetylcysteine was studied by the HPLC-UV-VIS method. The reactions were conducted under three different pH conditions. HPLC-MS measurements confirmed the structure of the formed adducts. The chalcones reacted with both thiols under all incubation conditions. The initial rate and composition of the equilibrium mixtures depended on the ratio of the deprotonated form of the thiols. In the reaction of 4-methoxychalcone with N-acetylcysteine under strongly basic conditions, transformation of the kinetic adduct into the thermodynamically more stable one was observed. Addition of S-protonated N-acetylcysteine onto the polar double bonds of the chalcones showed different degrees of diastereoselectivity. Both chalcones showed a Michael-type addition reaction with the ionized and non-ionized forms of the investigated thiols. The initial reactivity of the chalcones and the equilibrium composition of the incubates showed a positive correlation with the degree of ionization of the thiols. Conversions showed systematic differences under each set of conditions. The observed differences can hint at the difference in reported biological actions of 4-methyl- and 4-methoxy-substituted chalcones.

scholarly journals Enamel interproximal reduction during treatment with clear aligners: digital planning versus OrthoCAD analysis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Giuseppina Laganà ◽  
Arianna Malara ◽  
Roberta Lione ◽  
Carlotta Danesi ◽  
Simonetta Meuli ◽  
...  
Keyword(s):  
Treatment Plan ◽  
End Of Treatment ◽  
The Mean ◽  
The Difference ◽  
Dependent Sample ◽  
University Of Rome ◽  
The University ◽  
Enamel Reduction ◽  
Lower Arch

Abstract Background The aim of the study was to compare the amount of interproximal enamel reduction (IPR) provided on ClinCheck software with the amount of IPR carried out by the orthodontist during treatment with clear aligners. Methods 30 subjects (14 males, 16 females; mean age of 24.53 ± 13.41 years) randomly recruited from the Invisalign account of the Department of Orthodontics at the University of Rome “Tor Vergata” from November 2018 to October 2019, were collected according to the following inclusion criteria: mild to moderate dento-alveolar discrepancy (1.5–6.5 mm); Class I canine and molar relationship; full permanent dentition (excluding third molars); both arches treated only using Comprehensive Package by Invisalign system; treatment plan including IPR. Pre- (T0) and post-treatment (T1) digital models (.stl files), created from an iTero scan, were collected from all selected patients. The OrthoCAD digital software was used to measure tooth mesiodistal width in upper and lower arches before (T0) and at the end of treatment (T1) before any refinement. The widest mesio-distal diameter was measured for each tooth excluding molars by “Diagnostic” OrthoCAD tool. The total amount of IPR performed during treatment was obtained comparing the sum of mesio-distal widths of all measured teeth at T0 and T1. Significant T1–T0 differences were tested with dependent sample t-test (P < 0.05). Results In the upper arch, IPR was digitally planned on average for 0.62 mm while in the lower arch was on average for 1.92 mm. As for the amount of enamel actually removed after IPR performing, it was on average 0.62 mm in the maxillary arch. In the mandibular arch, the mean of IPR carried out was 1.93 mm. The difference between planned IPR and performed IPR is described: this difference was on average 0.00 mm in the upper arch and 0.01 in the lower arch. Conclusions The amount of enamel removed in vivo corresponded with the amount of IPR planned by the Orthodontist using ClinCheck software.

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