The use of chromium oxide to estimate the faecal output of Merinos

1963 ◽  
Vol 14 (2) ◽  
pp. 239 ◽  
Author(s):  
LJ Lambourne ◽  
TF Reardon
Keyword(s):  
Chromium Oxide ◽  
Grab Sampling ◽  
Low Concentrations ◽  
Wide Range ◽  
Main Series ◽  
Series Of Experiments ◽  
The Mean ◽  
High Concentrations ◽  
Fixed Times ◽  
Selection Of

The pattern of chromium oxide (Cr2O3) excretion was studied in Merino wethers. The sheep were dosed twice daily with Cr2O3 at fixed times. In the main series of experiments, sheep were fed fresh herbage in metabolism pens. An oaten chaff diet was also employed. In all cases a diurnal pattern of Cr2O3 excretion in the faeces was observed. The pattern was not consistent from day to day, nor was there any consistent effect of level of intake or feeding frequency on the excretion pattern. Distributions of Cr2O3 were examined in eight grazing sheep killed ½–4 hr after dosing. In six of the animals high concentrations of the marker were found to be mixed with the reticuloruminal ingesta, while low concentrations were observed in the other stomachs. In the remaining two animals high concentrations were observed in the omasum and abomasum, from which it was inferred that the dose had by-passed the main bulk of the reticulorurninal ingesia. It seems unlikely that any real advantage is to be gained by painstaking selection of particular times for dosing and faeces sampling in different environments; and it is suggested that convenient fixed times — say 6 a.m. and 3 p.m., or 9 a.m. and 5 p.m. — should prove satisfactory in estimating output of faeces of grazing animals under a wide range of conditions. In 40 sheep-periods of 10–14 days, the mean daily output of faeces organic matter by pen-fed wethers was estimated with mean 101% and error ±12% of the true figures, by analysis of a single bulked sample obtained by dosing and grab sampling at about 9 a.m. and 5 p.m. daily. In 40 periods when samples were bulked over 5–7 days the average estimate was 102 ± 14% of the true figure. Comparison under extensive grazing conditions showed that estimates obtained by dosing and sampling only once per day were generally some 15% higher than those obtained by dosing and sampling twice daily.

scholarly journals Gelation or molecular recognition; is the bis-(α,β-dihydroxy ester)s motif an omnigelator?

2010 ◽  
Vol 6 ◽  
pp. 1079-1088 ◽  
Author(s):  
Peter C Griffiths ◽  
David W Knight ◽  
Ian R Morgan ◽  
Amy Ford ◽  
James Brown ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Neutron Scattering ◽  
Spin Echo ◽  
Inelastic Neutron ◽  
Gelation Mechanism ◽  
Regular Structures ◽  
Low Concentrations ◽  
Wide Range ◽  
History Of ◽  
Selection Of

Understanding the gelation of liquids by low molecular weight solutes at low concentrations gives an insight into many molecular recognition phenomena and also offers a simple route to modifying the physical properties of the liquid. Bis-(α,β-dihydroxy ester)s are shown here to gel thermoreversibly a wide range of solvents, raising interesting questions as to the mechanism of gelation. At gelator concentrations of 5–50 mg ml−1, gels were successfully formed in acetone, ethanol/water mixtures, toluene, cyclohexane and chloroform (the latter, albeit at a higher gelator concentration). A range of neutron techniques – in particular small-angle neutron scattering (SANS) – have been employed to probe the structure of a selection of these gels. The universality of gelation in a range of solvent types suggests the gelation mechanism is a feature of the bis-(α,β-dihydroxy ester) motif, with SANS demonstrating the presence of regular structures in the 30–40 Å range. A correlation between the apparent rodlike character of the structures formed and the polarity of the solvent is evident. Preliminary spin-echo neutron scattering studies (SESANS) indicated the absence of any larger scale structures. Inelastic neutron spectroscopy (INS) studies demonstrated that the solvent is largely unaffected by gelation, but does reveal insights into the thermal history of the samples. Further neutron studies of this kind (particularly SESANS and INS) are warranted, and it is hoped that this work will stimulate others to pursue this line of research.

Effects of polymethoxylated flavone metabolites on apoB100 secretion and MTP activity in Huh7.5 cells

2021 ◽  
Vol 18 ◽  
Author(s):  
Danielle R. Gonçalves ◽  
Thais B. Cesar ◽  
John A. Manthey ◽  
Paulo I. Costa
Keyword(s):  
Lipid Synthesis ◽  
Dependent Manner ◽  
Transfer Protein ◽  
Low Concentrations ◽  
Wide Range ◽  
Cell Assays ◽  
Polymethoxylated Flavones ◽  
High Concentrations

Background: Citrus polymethoxylated flavones (PMFs) reduce the synthesis of liver lipoproteins in animal and in vitro cell assays, but few studies have evaluated the direct effects of their metabolites on this highly regulated process. Objective: To investigate the effects of representative metabolites of PMF on the secretion of liver lipoproteins using the mammalian cell Huh7.5. Method: In this study, the influences of three PMFs and five previously isolated PMF metabolites on hepatic apoB-100 secretion and microsomal transfer protein (MTP) activity were evaluated. Tangeretin (TAN), nobiletin (NOB) and 3,5,6,7,8,3′,4′-heptamethoxyflavone (HMF), and their glucuronides (TAN-Gluc, NOB-Gluc and HMF-Gluc) and oxidatively demethylated metabolites (TAN-OH, NOB-OH, HMF-OH) were incubated with Huh7.5 cells to measure their inhibitory effects on lipid synthesis. Results: The results showed that TAN, HMF and TAN-OH reduced the secretion of apoB-100 in a dose-dependent manner, while NOB and the other tested metabolites showed no inhibition. MTP activity in the Huh7.5 cells was significantly reduced in the presence of low concentrations of TAN, and in high concentrations of NOB-OH. This study also showed that PMFs and PMF metabolites produced a wide range of effects on apoB-100 secretion and MTP activity. Conclusion: The results suggest that while PMFs and their metabolites control dyslipidemia in vivo, the inhibition of MTP activity cannot be the only pathway influenced by these compounds.

THE CUT-OFF POINT IN SUB-CLINICAL OBSESSIVE-COMPULSIVE RESEARCH

2000 ◽  
Vol 28 (3) ◽  
pp. 225-233 ◽  
Author(s):  
David Mataix-Cols ◽  
Julio Vallejo ◽  
Miquel Sànchez-Turet
Keyword(s):  
Selection Criteria ◽  
Methodological Issue ◽  
Theoretical Models ◽  
Control Group ◽  
Personality Measures ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Wide Range ◽  
The Mean ◽  
Selection Of

The question of which cut-off point would be more appropriate in the selection of sub-clinical obsessive-compulsive (OC) samples is an important methodological issue that has not been formally addressed, hence prompting the current study. Three groups of sub-clinical OC subjects, scoring 1, 1.5, and 2 standard deviations (SD) above the mean on the Padua Inventory, and a matched non-OC control group, were compared on various clinical and personality measures. As expected, the three sub-clinical groups had higher scores than the non-OC group on measures of OC symptoms (including obsessional slowness), depression, anxiety, and on personality measures of neuroticism, psychoticism, and obsessional traits. However, no significant differences were observed between the three sub-clinical groups on most measures, although the 2 SD group had higher scores on neuroticism and obsessional personality traits. It is concluded that a wide range of selection criteria can yield similar results that are interpretable within the current theoretical models of Obsessive-Compulsive Disorder (OCD). It is suggested that subjects with a diagnosis of OCD should be carefully excluded from sub-clinical studies. [A Spanish abstract follows the references.]

scholarly journals Dosimetry of Critical Organs in Maxillofacial Imaging with Cone-beam Computed Tomography

2019 ◽  
Vol 9 (1Feb) ◽  
Author(s):  
R Ghanbarnezhad Farshi ◽  
A Mesbahi ◽  
M Johari ◽  
Ü Kara ◽  
N Gharehaghaji
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Radiation Doses ◽  
Parotid Glands ◽  
Thermoluminescent Dosimeters ◽  
Wide Range ◽  
Significant Difference ◽  
The Mean ◽  
Selection Of

Background: While the benefits of cone-beam computed tomography (CBCT) are well known in maxillofacial imaging, the use of this modality is not risk-free.Objective: The aim of this study was to evaluate the exposure doses received by patients during maxillofacial imaging with CBCT.Methods: Entrance surface dose (ESD) was measured by using thermoluminescent dosimeters (TLDs) attached to the eyes lids, parotid glands and thyroid of 64 patients in two imaging centers (A and B). Phantom dosimetry was performed by a cylindrical poly-methyl methacrylate (PMMA) head-size phantom and an ionization chamber for different exposure parameters. NewTom VGi and Planmeca Promax 3D CBCT scanners were used at centers A and B, respectively.Results: The mean ESD of the eyes, parotid glands and thyroid were 2.57, 2.33 and 0.28 mGy in center A, 0.35, 2.11 and 0.37 mGy in center B, respectively. ESD of the eyes revealed a significant difference in two centers; in center B, it was 86.4% lower than center A. In the phantom dosimetry, the measured doses of NewTom VGi were 2.63 and 2.08 mGy, respectively by changing field of view (FOV) size from 8×8 cm2 (height × diameter) to 6×6 cm2. For Planmeca Promax 3D, it ranged from 0.98 to 3.24 mGy depending on exposure parameters.Conclusion: There is a wide range of radiation doses dependent on the units, patients and selected scan parameters. Inappropriate selection of exposure settings, especially FOV size, can seriously increase patient dose.

scholarly journals Combined action of binase and bleomycin toward human lung adenocarcinoma cells

2016 ◽  
Vol 62 (3) ◽  
pp. 279-282 ◽  
Author(s):  
P.V. Zelenikhin ◽  
A.V. Makeeva ◽  
T.N. Nguen ◽  
Y.A. Siraj ◽  
O.N. Ilinskaya
Keyword(s):  
Lung Adenocarcinoma ◽  
Human Lung ◽  
A549 Cells ◽  
Chemotherapeutic Agents ◽  
Human Lung Adenocarcinoma ◽  
Low Concentrations ◽  
Wide Range ◽  
Bacillus Pumilus Rnase ◽  
High Concentrations ◽  
Lung Adenocarcinoma A549

Some microbial ribonucleases (RNases) demonstrate selective cytotoxic effect against a wide range of tumor cells. In this context combined use of cytotoxic RNases in complex therapy with other chemotherapeutic agents appears to be especially promising. In this study we have investigated the apoptosis-induced effect of Bacillus pumilus RNase (binase) in combination with known anti-tumor antibiotic bleomycin on human lung adenocarcinoma A549 cells. The combined effect of high concentrations of these agents did not have any mutual increase in their apoptosis-induced action, while a combination of non-apoptotic concentrations resulted in the increase of the proportion of apoptotic cells up to 22% as compared with individual effect of bleomycin (6%) and binase (12%) used separately. These results indicate that binase and bleomycin are effective in combination of their low concentrations and ineffective in combination of their high concentrations.

THE ENOLASE OF THE HUMAN ERYTHROCYTE

1962 ◽  
Vol 40 (1) ◽  
pp. 1005-1018
Author(s):  
Rhoda Blostein ◽  
Orville F. Denstedt
Keyword(s):  
Kinetic Study ◽  
Human Erythrocyte ◽  
Hydrogen Ion ◽  
Active Complex ◽  
Ion Concentrations ◽  
Enzyme Substrate ◽  
Low Concentrations ◽  
Absolute Requirement ◽  
Wide Range ◽  
High Concentrations

The enolase activity of the human erythrocyte has been studied with a partially purified preparation of the enzyme. The enzyme was found to have an absolute requirement for Mg2+ions. A kinetic study of the influence of the concentration of Mg ions and 2-phosphoglycerate on the formation of phosphoeno/pyruvate from 2-phosphoglycerate has shown that the active complex of enzyme, substrate, and activator (Mg2+) can be formed in several ways. With low concentrations of substrate and Mg2+the reaction was maximum at pH 7.0; with high concentrations of both, the activity was maximum over a wide range of hydrogen ion concentrations on the acid side of neutrality (at least from pH 6.3 to 7.0) and decreased above pH 7.0.

Concanavalin-A-mediated thymocyte agglutination: a model for a quantitative study of cell adhesion

1982 ◽  
Vol 56 (1) ◽  
pp. 21-48
Author(s):  
C. Capo ◽  
F. Garrouste ◽  
A.M. Benoliel ◽  
P. Bongrand ◽  
A. Ryter ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Quantitative Study ◽  
Concanavalin A ◽  
Cell Metabolism ◽  
Quantitative Model ◽  
Experimental Conditions ◽  
Wide Range ◽  
Binding Probability ◽  
The Mean ◽  
High Concentrations

This report describes a quantitative study of the agglutination of rat thymocytes with concanavalin A (ConA). The probability that two ConA-coated cells remain bound after centrifugation was determined over a wide range of lectin concentrations. The minimal force required to separate agglutinated cells and the number of ConA molecules bound per cell were measured in similar experimental conditions. Agglutinated cells were examined by electron microscopy to estimate the area of membrane involved in adhesion. The dependence of agglutination on cell metabolism was studied: cold (4 degrees C), sodium azide (15 mM) and cytochalasin B (10 micrograms/ml) inhibited thymocyte adhesion. The importance of lateral movements of ConA molecules was assayed by measuring the adhesion of ConA-coated glutaraldehyde-fixed thymocytes to untreated cells: substantial binding occurred, but at a reduced level relative to untreated cells. A mathematical analysis of experimental data allowed the following conclusions. (1) At least 10(3) ConA bonds were involved in cross-linking two bound cells, which required the lectin molecules to be concentrated in the binding area, at least when low ConA concentrations (0.5 microgram/ml or less) were used. (2) The dependence of the binding probability on lectin concentration was fairly linear when the latter was small, which implied that the limiting step in cell-cell adhesion was the formation of a bond between a single ConA molecule and a ligand on the other cell. (3) The mean intercellular-contact time for the formation of this first bond was about 10 S for high concentrations of ligand (8 micrograms/ml). It was possible to fit the above data into a physically consistent quantitative model of cell adhesion.

Expression of tenascin mRNA in mesoderm during Xenopus laevis embryogenesis: the potential role of mesoderm patterning in tenascin regionalization

Development ◽  
1992 ◽  
Vol 116 (1) ◽  
pp. 147-157
Author(s):  
M. Umbhauer ◽  
J.F. Riou ◽  
J. Spring ◽  
J.C. Smith ◽  
J.C. Boucaut
Keyword(s):  
Cdna Probe ◽  
Pcr Amplification ◽  
Lateral Plate ◽  
Complex Process ◽  
Low Concentrations ◽  
Tailbud Stage ◽  
Series Of Experiments ◽  
High Concentrations ◽  
Restricted Pattern

In Xenopus embryos, the extracellular matrix (ECM) protein tenascin (TN) is expressed dorsally in a very restricted pattern. We have studied the spatial and temporal expression of TN mRNA in tailbud-stage embryos by RNAase protection and in situ hybridization using a cDNA probe for Xenopus TN obtained by PCR amplification. We report that TN transcripts are principally expressed in cells dispersed around the neural tube and notochord as well as in myotome and sclerotome cells. No TN mRNA could be detected in lateral plate mesoderm, but expression was detectable beneath tail fin epidermis. In a second series of experiments, we studied the expression of TN mRNA and protein in combinations between animal and vegetal stage-6 blastomeres and in stage-8 blastula animal caps treated with activin A or basic fibroblastic growth factor (b-FGF). Isolated animal cap tissue cultured alone differentiates into epidermis, which expresses neither TN protein nor TN mRNA. TN expression is, however, elicited in response to isolated dorsal vegetal blastomeres and in response to high concentrations of activin, both of which treatments lead to formation of muscle and/or notochord. Low concentrations of activin, and ventral vegetal blastomeres, treatments that induce mesoderm of ventral character, are poor inducers of TN. However, b-FGF, which also induces ventral mesoderm, elicits strong expression. These results indicate that TN regionalization is a complex process, dependent both on the pattern of differentiation of mesodermal tissues and on the agent with which they are induced. The data further show that “ventral mesoderm” induced by low concentrations of activin is distinct from that induced by b-FGF, and imply that activin induces ventral mesoderm of the trunk while b-FGF induces posterior mesoderm of the tailbud.

scholarly journals Chemical characteristics of the snow pits at Murododaira, Mount Tateyama, Japan

2011 ◽  
Vol 52 (58) ◽  
pp. 102-110 ◽  
Author(s):  
Koichi Watanabe ◽  
Yukiko Saito ◽  
Syoko Tamura ◽  
Yuki Sakai ◽  
Nagisa Eda ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Japan Sea ◽  
Coarse Grain ◽  
Central Japan ◽  
Low Concentrations ◽  
The Japan Sea ◽  
The Mean ◽  
High Concentrations ◽  
High Peroxide ◽  
Snow Precipitation

AbstarctMeasurements of the chemical composition of the snow pits at Murododaira (2450m a.s.l.), Mount Tateyama, near the coast of the Japan Sea in central Japan, were performed each spring from 2005 through 2008. The mean concentrations of nssSO42– and NO3– are higher than those in snowpack in the 1990s. The pH and nssCa2+ were usually high in the upper parts of 2–3m of snow deposited in the spring, when Asian dust (Kosa) particles are frequently transported. High concentrations of nssSO42– were detected in both the spring and winter layers. The high-nssCa2+ layers usually contained high concentrations of nssSO42–. The results show that not only Kosa particles but also air pollutants might have been transported long-range from the continent of Asia. The concentrations of peroxides were high in the new snow (precipitation particles) and granular snow (coarse grain, melt forms) layers. The peroxide concentrations in the snow layers were negatively correlated with the nssCa2+ concentrations. High peroxide concentrations may be preserved in granular snow layers having low concentrations of nssCa2+.

Germination biology of four climatically varied populations of the invasive species African lovegrass (Eragrostis curvula)

Weed Science ◽  
2021 ◽  
pp. 1-9
Author(s):  
Jason Roberts ◽  
Singarayer Florentine ◽  
Eddie van Etten ◽  
Christopher Turville
Keyword(s):  
Invasive Species ◽  
Environmental Factors ◽  
Perennial Grass ◽  
Complete Darkness ◽  
Eragrostis Curvula ◽  
Wide Range ◽  
The Mean ◽  
Global Biodiversity ◽  
Alternating Temperature ◽  
Selection Of

Abstract African lovegrass [Eragrostis curvula (Schrad.) Nees] is a highly invasive C4 perennial grass that threatens global biodiversity. Appropriate management of this species has been hampered by a lack of knowledge concerning its seed ecology, resulting in significant economic and environmental impacts within various environments. Consequently, this study explored the effects of a selection of environmental factors (photoperiod, alternating temperature, pH, and salinity) by analyzing several measures of germination on four geographically distinct populations of E. curvula to assist in its extirpation from infested sites. Seeds were collected in Australia from Maffra and Shepparton, VIC; Tenterfield, NSW; and Midvale, WA. Key results showed that seeds from Maffra (54% vs. 79%), Tenterfield (38% vs. 61%), and Shepparton (34% vs. 71%) had significantly reduced germination in complete darkness compared with an alternating 12-h light and 12-h dark photoperiod, whereas Midvale had consistent germination (91% vs. 99%). Temperatures between 17/7 C reduced germination for Maffra (42% vs. 73%), Tenterfield (34% vs. 55%), and Shepparton (33% vs. 59%) compared with the mean of all other temperature combinations, whereas Midvale had consistent germination. Furthermore, germination for all populations was consistent between pH 4 and 9. For salinity, germination was significantly reduced at ≥100 mM for Maffra (29% vs. 67%), ≥150 mM for Tenterfield (29% vs. 94%) and Shepparton (39.5% vs. 81.5%), and 250 mM for Midvale (39% vs. 82%) compared with the mean of all other concentrations. Although each trial was conducted independently, the data can be used to generate species-targeted management. Such strategies include maintaining high levels of quarantine and hygiene programs to avoid future spread; where practical, applying light-limiting strategies (mulching, tilling, or scraping) for the Maffra, Tenterfield, and Shepparton populations; and maintaining management efforts year-round, as the species can germinate under a wide range of conditions.

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