THE ROLE OF CALCITE AND GYPSUM IN THE LEACHING OF POTASSIUM IN A SANDY SOIL

2003 ◽  
Vol 39 (4) ◽  
pp. 379-394 ◽  
Author(s):  
M. JALALI ◽  
D. L. ROWELL
Keyword(s):  
Saline Water ◽  
Calcareous Soils ◽  
Similar Rate ◽  
Distilled Water ◽  
Untreated Soil ◽  
Controlled Processes ◽  
Unamended Soil ◽  
Rate Controlled ◽  
Rate Of Movement

Pulses of potassium (K+) applied to columns of repacked calcium (Ca2+) saturated soil were leached with distilled water or calcium chloride (CaCl2) solutions of various concentrations at a rate of 12 mm h−1. With increased Ca2+ concentration, the rate of movement of K+ increased, as did the concentration of K+ in the displaced pulse, which was less dispersed. The movement of K+ in calcite-amended soil leached with water was at a similar rate to that of the untreated soil leached with 1 mM CaCl2, and in soil containing gypsum, movement was similar to that leached with 15 mM CaCl2. The Ca2+ concentrations in the leachates were about 0.4 and 15 mM respectively, the expected values for the dissolution of the two amendments. Soil containing native K+ was leached with distilled water or CaCl2 solutions. The amount of K+ leached increased as Ca2+ concentration increased, with up to 34 % of the exchangeable K+ being removed in five pore volumes of 15 mM CaCl2. Soil amended with calcite and leached with water lost K+ at a rate between that for leaching the unamended soil with 1 mM CaCl2 and that with water. Soil containing gypsum and leached with water lost K+ at a similar rate to unamended soil leached with 15 mM CaCl2. The presence of Ca2+ in irrigation water and of soil minerals able to release Ca2+ are of importance in determining the amounts of K+ leached from soils.The LEACHM model predicted approximately the displacement of K+, and was more accurate with higher concentrations of displacing solution. The shortcomings of this model are its inability to account for rate-controlled processes and the assumption that K+: Ca2+ exchange during leaching can be described using a constant adsorption coefficient. As a result, the pulse is predicted to appear a little earlier and the following edge has less of a tail than that measured. In practical agriculture, the model will be more useful in soils containing gypsum or leached with saline water than in either calcareous or non-calcareous soils leached with rainwater.

Effect of Undernutrition During the Perinatal Period on Caries Development in the Rat: II. Caries Susceptibility in Underfed Rats Supplemented with Protein or Caloric Additions During the Suckling Period

1973 ◽  
Vol 52 (4) ◽  
pp. 680-687 ◽  
Author(s):  
Lewis Menaker ◽  
Juan M. Navia
Keyword(s):  
Dental Caries ◽  
Perinatal Period ◽  
Protein Deficiency ◽  
Specific Role ◽  
Protein Supplement ◽  
Distilled Water ◽  
Suckling Period ◽  
Rat Pups ◽  
Low Incidence

The specific role of protein deficiency in altering dental caries incidence in rat pups was investigated. A 10% protein supplement given to undernourished rats during development allowed them to overcome weight deficiencies and reversed dental caries to the low incidence found in well-nourished control rats. Caries in undernourished rats supplemented with an isocaloric, proteinfree solution, was as high as that of undernourished rats intubated with distilled water.

scholarly journals Habit and Skill in the Domain of Joint Action

Topoi ◽  
2020 ◽  
Author(s):  
Judith H. Martens
Keyword(s):  
Joint Action ◽  
Human Agency ◽  
Individual Action ◽  
Complex Action ◽  
Controlled Processes ◽  
Know How ◽  
Joint Agency ◽  
Nuanced Understanding ◽  
Skillful Action

AbstractDichotomous thinking about mental phenomena is abundant in philosophy. One particularly tenacious dichotomy is between “automatic” and “controlled” processes. In this characterization automatic and unintelligent go hand in hand, as do non-automatic and intelligent. Accounts of skillful action have problematized this dichotomous conceptualization and moved towards a more nuanced understanding of human agency. This binary thinking is, however, still abundant in the philosophy of joint action. Habits and skills allow us agentic ways of guiding complex action routines that would otherwise overwhelm our reflective capacities. In this paper, I look at how theories of skill, habit, and know-how in individual action can inform a non-dichotomous account of joint action. I argue that a fuller understanding of joint agency has to understand not only group know-how, but also the role of attention and the highly integrated types of control that allow agents to act together.

scholarly journals Effect of Aging on the Cornea of Male Albino Rat and Possible Therapeutic Role of Royal Jelly

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
H R Elareny ◽  
A I Ahmed ◽  
A F Alneklawy ◽  
M K Tawfik
Keyword(s):  
Royal Jelly ◽  
Male Rats ◽  
Distilled Water ◽  
Oral Gavage ◽  
Albino Rat ◽  
Therapeutic Role ◽  
Once Daily ◽  
Group I ◽  
Group Ii

Abstract Introduction Nowadays interest in aging has greatly increased, Aging is a complex natural process involving every molecule, cell, and organ in the body that is associated with tissue dysfunction in many organs. Aging of the cornea causes major eye effects and leads to substantial cost in medical and social terms. These effects include the highly prevalent dry eye disease (DED) that affects both visual function and quality of life in elderly. Symptoms of (DED) include, ocular pain, visual disturbances, and increase lacrimation. Functional foods such as Royal jelly (RJ) have a growing attention because of consumers increasing concerns about their health. Its importance not only for its nutritional properties but also for its functional and biological properties such as antioxidant, anti-inflammatory, antibacterial, antiviral, and anti-ulcerous activities. It is used as a cheap natural source in daily life and medicine. (RJ) is a complex substance composed of proteins, sugars, lipids, amino acids, vitamins, and minerals. Aim The present study aimed to investigate the histological effect of aging on the cornea of male albino rat and possible therapeutic role of (RJ) on senile group. Materials and Methods Twenty-four male albino rats were used in this study divided into Group I: consisted of 6 adult male rats aged 3- 6 months. Group II: consisted of 18 senile male rats aged 18-24 months, were further subdivided into three subgroups as follows: Group II A: (n = 6) negative control senile rats, not subjected to any procedure for 4 weeks. Group II B: (n = 6) control senile rats and were given distilled water by oral gavage once daily for 4 weeks. Group II C: (n = 6) senile rats were given (RJ) by oral gavage dissolved in distilled water once daily for 4 weeks. At the end of the experiment, rats were sacrificed after being deeply anesthetized with ether according to the protocol of the Committee of Animal Research Ethics (CARE). The cornea of each animal was carefully dissected out after death and immediately fixed in 10% formalin for preparation of paraffin blocks 5 micrometer thickness. Sections were stained with hematoxylin and eosin (I-I&E), Masson's trichrome and periodic acid-Schiff (PAS). Statistical analysis and quantitative morphometric study were done. Results Light microscopic examination of corneas of senile rats revealed different pathological changes included irregularity in the surface epithelium as well as surface erosions and cytoplasmic vacuolations. The stroma showed widely separated collagen fibers with decreased keratocyte density. It was concluded that (RJ) supplementation to senile rats obviously unproved all layers of the cornea histologically.

The role of sodium chloride in the process of induction by lithium chloride in cells of the Rana pipiens gastrula

Development ◽  
1968 ◽  
Vol 19 (3) ◽  
pp. 387-396
Author(s):  
Lester G. Barth ◽  
Lucena J. Barth
Keyword(s):  
Sodium Chloride ◽  
Culture Medium ◽  
Rana Pipiens ◽  
Divalent Cations ◽  
Pigment Cells ◽  
Distilled Water ◽  
Sodium Ions ◽  
Monovalent Cations ◽  
High Concentration

A study of the effects of a series of monovalent cations, Li+, Na+ and K+, and a series of divalent cations, Mn2+, Ca2+ and Mg2+, upon small aggregates of cells taken from the presumptive epidermis of Rana pipiens gastrulae revealed that these ions induce nerve and pigment cells (Barth, 1965). The effectiveness of both series of ions as inductors was similar to their effects on decreasing the electrophoretic mobility of DNA as determined by Ross & Scruggs (1964). When it was found that sucrose in glass-distilled water also would induce nerve and pigment cells the role of ions as inductors came under closer scrutiny. A study of the nature of the induction by sucrose revealed that a relatively high concentration of sodium ions was necessary in the culture medium used after sucrose treatment (Barth, 1966).

scholarly journals Loss of PTEN in Fallopian Tube Epithelium Results in Multicellular Tumor Spheroid Formation and Metastasis to the Ovary

Cancers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 884 ◽  
Author(s):  
Matthew Dean ◽  
Vivian Jin ◽  
Tova M. Bergsten ◽  
Julia R. Austin ◽  
Daniel D. Lantvit ◽  
...  
Keyword(s):  
Fallopian Tube ◽  
Single Gene ◽  
Similar Rate ◽  
Genetic Alterations ◽  
Wild Type ◽  
Spheroid Formation ◽  
Multicellular Tumor Spheroid ◽  
Ovarian Stroma

High-grade serous ovarian cancer (HGSOC) can originate in the fallopian tube and then spread to the ovary. Our objective was to evaluate the role of multicellular tumor spheroids (MTS) in ovarian metastasis. By testing a panel of murine oviductal epithelial (MOE) cells with genetic alterations mimicking those seen in HGSOC, we found that loss of PTEN allowed MTS formation under ultra-low adhesion conditions. Confirming these results in vivo, MTS-like structures were observed in the oviducts of PAX8Cre/+ PTENflox/flox mice. MOE PTENshRNA cells could incorporate up to 25% wild type cells into MTS, while higher percentages of wild type cells resulted in a loss of MTS formation. MTS formation allowed MOE PTENshRNA cells to survive better under ultra-low adhesion conditions than control cells. MTS also attached to the ovarian stroma, as would be exposed during ovulation. Interestingly, MTS more robustly cleared monolayers of murine ovarian surface epithelia than murine ovarian fibroblasts. When xenografted into the ovarian bursa, OVCAR8 MTS were able to form tumors in the ovary at a similar rate as an equal number of OVCAR8 cells grown on traditional cell culture plastic. In conclusion, loss of a single gene (PTEN) allows the fallopian tube epithelia to form MTS, which survive better under ultra-low adhesion conditions, attach to the extracellular matrix exposed during ovulation, and colonize the ovary. These results suggest that MTS may contribute to seeding of the ovary in HGSOC patients.

Biphasic response to acetylcholine in human veins in vivo: the role of the endothelium

1990 ◽  
Vol 78 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Joe Collier ◽  
Patrick Vallance
Keyword(s):  
Dose Response ◽  
Distilled Water ◽  
Low Doses ◽  
Biphasic Response ◽  
Dorsal Hand ◽  
Before And After ◽  
Higher Doses ◽  
Made In

1. The dose-response to acetylcholine has been examined in dorsal hand veins of healthy volunteers before and after removal of the endothelium. 2. Measurements were made in single dorsal hand veins during local infusions of acetylcholine. The vein was irrigated with distilled water to remove the endothelium. Dilator studies were performed in vessels preconstricted by a continuous infusion of noradrenaline. 3. In the endothelium-intact vessel the dose-response to acetylcholine was biphasic; low doses produced venodilatation with higher doses causing venoconstriction. 4. Dilatation to low doses of acetylcholine was abolished by prior irrigation with distilled water, consistent with denudation of the endothelium by this process. Irrigation augmented the constriction seen in response to higher doses of acetylcholine. 5. This is the first demonstration of an endothelium-dependent biphasic dose-response to acetylcholine in man. The results raise questions as to the possible physiological actions of endogenous acetylcholine and as to the use of the acetylcholine dose-response curve as a marker of endothelial function.

The role of allelopathy in legume decline in pastures. III. Tolerance of subterranean clover lines to the allelopathic compounds released from Phalaris residues

1995 ◽  
Vol 46 (5) ◽  
pp. 1039 ◽  
Author(s):  
JH Leigh ◽  
DM Halsall ◽  
WJ Muller ◽  
RN Oram ◽  
JP Edlington ◽  
...  
Keyword(s):  
Performance Index ◽  
Root Length ◽  
Mediterranean Region ◽  
Cold Water ◽  
Subterranean Clover ◽  
Distilled Water ◽  
Trifolium Subterraneam ◽  
Allelopathic Compounds

The tolerance of 126 lines of subterranean clover (Trifolium subterraneam L.) to allelochemicals released in cold water leachate from dry herbage of phalaris (Phalaris aquatica L. cv. Australian) was examined and compared. The lines were 112 accessions from grassy associations in the Mediterranean region and 14 Australian cultivars. Measures of germination, radicle length, nodulation and root length in seedlings exposed to three concentrations of extract relative to those obtained from seedlings exposed to distilled water only were obtained. A performance index for each line was derived from these measures. Large differences between lines for these four parameters were evident. On the basis of these comparisons, scope exists to select and recommend lines of subclover which are tolerant to these allelochemicals and thus are capable of higher production and greater persistence in long-term perennial phalaris pastures.

Attitudes and Behavior

2020 ◽  
Author(s):  
Geoffrey Haddock ◽  
Sapphira Thorne ◽  
Lukas Wolf
Keyword(s):  
Primary Reason ◽  
Controlled Processes ◽  
Social Lives ◽  
History Of Research ◽  
History Of ◽  
Attitude Behavior ◽  
The Individual ◽  
And Behavior ◽  
Attitudes And Behavior

Attitudes refer to overall evaluations of people, groups, ideas, and other objects, reflecting whether individuals like or dislike them. Attitudes have been found to be good predictors of behavior, with generally medium-sized effects. The role of attitudes in guiding behavior may be the primary reason why people’s social lives often revolve around expressing and discussing their attitudes, and why social psychology researchers have spent decades examining attitudes. Two central questions in the study of attitudes concern when and how attitudes predict behavior. The “when” question has been addressed over decades of research that has identified circumstances under which attitudes are more or less likely to predict behavior. That is, attitudes are stronger predictors of behaviors when both constructs are assessed in a corresponding or matching way, when attitudes are stronger, and among certain individuals and in certain situations and domains. The “how” question concerns influential models in the attitudes literature that provide a better understanding of the processes through which attitudes are linked with behaviors. For instance, these models indicate that other constructs need to be taken into account in understanding the attitude-behavior link, including intentions to perform a behavior, whether individuals perceive themselves to be in control of their behavior, and what they believe others around them think the individual should do (i.e., norms). The models also describe whether attitudes relate to behavior through relatively deliberative and controlled processes or relatively automatic and spontaneous processes. Overall, the long history of research on attitude-behavior links has provided a clearer prediction of when attitudes are linked with behaviors and a better understanding of the processes underlying this link.

Nucleocytoplasmic transport in yeast: a few roles for many actors

2010 ◽  
Vol 38 (1) ◽  
pp. 273-277 ◽  
Author(s):  
Jindriska Fiserova ◽  
Martin W. Goldberg
Keyword(s):  
Nuclear Pore Complex ◽  
Model Organism ◽  
Nucleocytoplasmic Transport ◽  
Present Review ◽  
Eukaryotic Cells ◽  
Nuclear Pore ◽  
Controlled Processes ◽  
Bidirectional Transport

Eukaryotic cells have developed a series of highly controlled processes of transport between the nucleus and cytoplasm. The present review focuses on the latest advances in our understanding of nucleocytoplasmic exchange of molecules in yeast, a widely studied model organism in the field. It concentrates on the role of individual proteins such as nucleoporins and karyopherins in the translocation process and relates this to how the organization of the nuclear pore complex effectively facilitates the bidirectional transport between the two compartments.

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