On the antennular secretion of the cyprid of Balanus amphitrite amphitrite, and its role as a settlement pheromone

1994 ◽  
Vol 74 (1) ◽  
pp. 243-250 ◽  
Author(s):  
Anthony S. Clare ◽  
Rebecca K. Freet ◽  
Marion McClary
Keyword(s):  
Linear Relationship ◽  
Density Effect ◽  
Balanus Amphitrite ◽  
Semibalanus Balanoides ◽  
Searching Behaviour ◽  
Positive Linear Relationship ◽  
Balanus Balanoides

In exploring a substratum, Balanus amphitrite amphitrite Darwin (Crustacea: Cirripedia) cyprids deposit ‘footprints’ of antennular secretion. The results of in vitro settlement assays suggest that in addition to serving as a temporary adhesive, the secretion acts as a pheromone, in that its presence induces the settlement of conspecific cyprids. This result is in accord with a previous study on Balanus balanoides (L.)(=Semibalanus balanoides). In settlement assays, the pheromone is likely to contribute to an observed positive linear relationship between settlement and cyprid density. The density effect should thus be an important consideration in the design of barnacle settlement assays. In the field, cyprid searching behaviour may render a surface more attractive to settlement by cypris larvae.

EFFECT OF VARIOUS PREPARATIONS OF PITUITARY AND DIENCEPHALON ON THE IN VITRO SECRETION OF ALDOSTERONE AND CORTICOSTERONE BY THE RAT ADRENAL GLAND

1961 ◽  
Vol 39 (5) ◽  
pp. 901-913 ◽  
Author(s):  
O. J. Lucis ◽  
I. Dyrenfurth ◽  
E. H. Venning
Keyword(s):  
Adrenal Gland ◽  
Linear Relationship ◽  
Dose Response ◽  
Response Curve ◽  
Maximum Effect ◽  
Percentage Increase ◽  
Aldosterone Secretion ◽  
Maximal Stimulation ◽  
Stimulation Of

Purified corticotropin and ACTH peptides increased the secretion of aldosterone, corticosterone, and an unidentified compound RT4in incubated rat adrenal tissue. When the response was expressed as a percentage increase above that of the control tissue, the increases in corticosterone and compound RT4followed a sigmoid log dose – response curve. The maximum effect on aldosterone was obtained at a time when the response curve for corticosterone assumed a linear relationship between the response and the logarithm of the dose of ACTH. This dose level was considerably less than that required for maximal stimulation of corticosterone.The capacity of the ACTH peptides α1+α2and δ′ for stimulating aldosterone secretion could be greatly diminished by allowing solutions of these fractions to stand at 5 °C for 1 week. These solutions still retained their ability to stimulate corticosterone secretion.Saline suspensions and extracts of fresh hog diencephalon contained a factor which selectively stimulated aldosterone secretion.

THE IN VITRO ACTION OF ACTH ON THE OXYGEN CONSUMPTION OF SLICES OF CATTLE ADRENAL CORTEX

1953 ◽  
Vol 9 (4) ◽  
pp. 379-390 ◽  
Author(s):  
M. REISS ◽  
EVA BRUMMEL ◽  
I. D. K. HALKERSTON ◽  
F. E. BADRICK ◽  
M. FENWICK
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Linear Relationship ◽  
Adrenal Cortex ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Biological Assay ◽  
Percentage Increase ◽  
Small Doses

A technique for measuring the action of small doses of ACTH on the oxygen consumption of slices of cattle adrenal cortex is described. The oxygen consumption rate of such slices in vitro is increased by ACTH. A linear relationship between logarithm of the dose of ACTH and the percentage increase in the rate of oxygen uptake is obtained with this method, and its suitability for biological assay purposes has been investigated. The question of the specificity of this action of ACTH is discussed.

scholarly journals Nutrient management on leaf area index of potato-mungbean- T. aman rice cropping pattern

2015 ◽  
Vol 39 (3) ◽  
pp. 515-527 ◽  
Author(s):  
MAH S Jahan ◽  
MAR Sarkar ◽  
M Salim
Keyword(s):  
Leaf Area Index ◽  
Linear Relationship ◽  
Leaf Area ◽  
Nutrient Management ◽  
Agricultural Research ◽  
Management Practice ◽  
Research Centre ◽  
Cropping Pattern ◽  
Area Index ◽  
Positive Linear Relationship

A field experiment was conducted at Regional Wheat Research Centre of the Bangladesh Agricultural Research Institute, Joydebpur, Gazipur, Bangladesh for 2 consecutive years during 2006-07 and 2007-08. The objective was to find out the optimum nutrient management practice on leaf area index of each component crop of potato-mungbean-T. Aman rice cropping pattern. Twelve nutrient management treatments were tested in RCBD with 3 replications. Treatments combination based on cropping pattern were T1=HYG (0-198-44- 194-24-6-1.2 for potato; 0-24-40-48-24-3-1.2 for mungbean ; 0-80-16-44-12-2-0 for T.Aman rice ), T2=MYG (0-140-34-138-18-4.5-0.9 for potato; 0-20-36-40- 20-2-1 for mungbean ; 0-56-12-32-8-1.5-0 for T.Aman rice), T3=IPNS (10000- 168-38-170-18-6-1.2 for potato ; 5000-9-37-36-21-3-1.2 for mungbean ; 5000- 65-13-32-9-2-0 for T.Aman rice), T4=STB (0-171-40-164-22-5-1 for potato; 0- 20-36-40-22-2-1 for mungbean ; 0-68-15-37-11-2-0 for T.Aman rice), T5=FP (0- 97-16-91-0-0-0 for potato ; 0-6-5-4-0-0-0 for mungbean ; 0-39-37-12-0-0-0 for T.Aman rice), T6=CON (0-0-0-0-0-0-0 for potato, mungbean and T.Aman rice) kg/ha CDNPKSZnB, T7=HYG+CRI, T8=MYG+CRI, T9=IPNS+CRI, T10=STB+CRI, T11=FP+CRI, T12=CON+CRI for potato-mungbean T.Aman rice cropping pattern, respectively. Average of two years data showed that HYG+CRI treatment gave maximum LAI followed by HYG, IPNS+CRI, IPNS, STB+CRI, and STB treatments at 60 days after planting (DAP) for potato, at 50 days after sowing (DAS) for mungbean, at 60 days after transplanting (DAT) for T.Aman rice, respectively. For potato, there was a significant (p?0.01) and positive linear relation between the LAI at 60 DAP and the tuber yield. While there was a significant (p?0.01) and positive linear relationship between the LAI at 50 DAS and seed yield of mungbean. In case of T.Aman rice, there was a significant (p?0.05) as well as positive linear relationship between the LAI at 60 DAT and the grain yield of rice. DOI: http://dx.doi.org/10.3329/bjar.v39i3.21994 Bangladesh J. Agril. Res. 39(3): 515-527, September 2014

scholarly journals Examination of the Relation between Strategic Leadership Expectations and Organizational Justice: A Research on Health Sector

2017 ◽  
Vol 8 (1) ◽  
pp. 109
Author(s):  
Ayhan Yalçınsoy ◽  
Cenk Aksoy
Keyword(s):  
Linear Relationship ◽  
Organizational Justice ◽  
Health Sector ◽  
Demographic Variables ◽  
Research Data ◽  
T Test ◽  
Healthcare Sector ◽  
Strategic Leadership ◽  
Positive Linear Relationship ◽  
The Relationship

The aim of this study is to examine the relationship between strategic leadership and organizational justice within the healthcare sector. In the context of the study, the introduced model was tested by a questionnaire instrument with 41 items excluding demographic variables. A total of 320 completed questionnaires were used for analysis. Correlation, regression, T test and Anova analyzes were applied to the research data that obtained by the questionnaire. The study focused on the employees of hospitals in the Diyarbakir province of Turkey. The results suggest that there is a very strong positive linear relationship between strategic leadership and organizational justice variables. The result of the study is consistent with the results of previous research. Also, some disparities were observed among the demographic variables of the study.

Determinants of LV diastolic function during atrial fibrillation: beat-to-beat analysis in acute dog experiments

2004 ◽  
Vol 286 (1) ◽  
pp. H145-H152 ◽  
Author(s):  
Tomotsugu Tabata ◽  
Richard A. Grimm ◽  
Junko Asada ◽  
Zoran B. Popović ◽  
Hirotsugu Yamada ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Linear Relationship ◽  
Diastolic Function ◽  
Left Ventricular ◽  
Ventricular Rate ◽  
Curvilinear Relationship ◽  
Pressure Curve ◽  
Positive Linear Relationship ◽  
Filling Time ◽  
Lv Diastolic Function

Left ventricular (LV) diastolic function during atrial fibrillation (AF) remains poorly understood due to the complex interaction of factors and beat-to-beat variability. The purpose of the present study was to elucidate the physiological determinants of beat-to-beat changes in LV diastolic function during AF. The RR intervals preceding a given cardiac beat were measured from the right ventricular electrogram in 12 healthy open-chest mongrel dogs during AF. Doppler echocardiography and LV pressure and volume beat-to-beat analyses were performed. The LV filling time (FT) and early diastolic mitral inflow velocity-time integral ( Evti) were measured using the pulsed Doppler method. The LV end-diastolic volume (EDV), peak systolic LV pressure (LVP), minimum value of the first derivative of LV pressure curve (dP/d tmin), and the time constant of LV pressure decay (τ) were evaluated with the use of a conductance catheter for 100 consecutive cardiac cycles. Beat-to-beat analysis revealed a cascade of important causal relations. LV-FT showed a significant positive linear relationship with Evti ( r = 0.87). Importantly, there was a significant positive linear relationship between the RR interval and LV-EDV in the same cardiac beat ( r = 0.53). Consequently, there was a positive linear relationship between LV-EDV and subsequent peak systolic LVP ( r = 0.82). Furthermore, there were significant positive linear and negative curvilinear relationships between peak systolic LVP and dP/d tmin ( r = 0.95) and τ ( r = –0.85), respectively, in the same cardiac beat. In addition, there was a significant negative curvilinear relationship between dP/d tmin and τ ( r = –0.86). We have concluded that the determinants of LV diastolic function in individual beats during AF depend strongly on the peak systolic LVP. This suggests that the major benefit of slower ventricular rate appears related to lengthening of LV filling interval, promoting subsequent higher peak systolic LVP and greater LV relaxation.

Studies on the Effect of Dose Size on the Absorption of beta-Carotene by the Rat in vivo

1999 ◽  
Vol 69 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Chen ◽  
Oace ◽  
Wolf
Keyword(s):  
Linear Relationship ◽  
Intestinal Mucosa ◽  
Beta Carotene ◽  
Intestinal Wall ◽  
Stomach Tube ◽  
Positive Linear Relationship ◽  
Intestinal Contents ◽  
Retinyl Esters ◽  
Dose Levels

This study was carried out to choose between two hypotheses with respect to the regulation of beta-carotene (BC) conversion to retinol in the whole animal: uptake of BC into intestinal mucosa is limited by saturation of an intestinal receptor; or the conversion to retinol is limited by saturation of the conversion enzyme(s). Groups of rats were given five different dose levels of labeled BC by stomach tube. Labeled and total BC and retinol were isolated from tissues and intestinal contents after 4 h. Results showed a positive linear relationship between BC in the intestinal wall and the dose administered, with no saturation level up to 1440 mug administered. Per cent formation of newly formed retinol from newly absorbed (i.e., labeled) BC was 20–26% of the three lower dose groups, 10% for the highest dose. No retinyl esters could be detected in the intestine. Most of the administered BC was in the intestinal contents, about 100-times more than in the intestinal wall and mucosa. Newly formed retinol in plasma was about 10-times that in liver. Small amounts of newly absorbed BC were found in liver, but no labeled retinyl esters. These results suggest that the absorption of BC is very inefficient; that it does not occur through an intestinal receptor; that the formation of retinol is regulated at the level of the conversion enzyme(s).

scholarly journals Impact of dietary oxidized protein on oxidative status and performance in growing pigs

2020 ◽  
Vol 98 (5) ◽  
Author(s):  
Carl A Frame ◽  
Erika Johnson ◽  
Logan Kilburn ◽  
Elisabeth Huff-Lonergan ◽  
Brian J Kerr ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Lipid Oxidation ◽  
Growth Performance ◽  
Linear Relationship ◽  
Dietary Protein ◽  
Protein Oxidation ◽  
Oxidative Status ◽  
Growing Pigs ◽  
Positive Linear Relationship

Abstract Rendered products from the meat industry can provide economical quality sources of proteins to the animal and feed industry. Similar to lipids, rendered proteins are susceptible to oxidation, yet the stability of these proteins is unclear. In addition, interest in understanding how oxidative stress can impact efficiency in production animals is increasing. Recent studies show that consumption of oxidized lipids can lead to a change in the oxidative status of the animal as well as decreases in production efficiency. To date, little is known about how consumption of oxidized proteins impacts oxidative status and growth performance. The objectives of this study were to determine if feeding diets high in oxidized protein to growing pigs would: 1) impact growth performance and 2) induce oxidative stress. Thirty pigs (42 d old; initial body weight [BW] 12.49 ± 1.45 kg) were randomly assigned to one of three dietary treatments with increasing levels of oxidized protein. Spray-dried bovine plasma was used as the protein source and was either unheated upon arrival, heated at 45 °C for 4 d, or heated at 100 °C for 3 d. Diets were fed for 19 d and growth performance was measured. Blood plasma (days 0 and 18), jejunum, colon, and liver tissues (day 19) were collected to analyze for markers of oxidative stress (e.g., protein oxidation, lipid oxidation, DNA damage, and glutathione peroxidase activity). Average daily gain (ADG;P < 0.01) and average daily feed intake (ADFI;P < 0.01) had a positive linear relationship to increased protein oxidation, but there was no effect on gain to feed ratio. Furthermore, protein (P = 0.03) and fat (P < 0.01) digestibility were reduced with increased protein oxidation in the diet. Crypt depth showed a positive linear relationship with dietary protein oxidation levels (P = 0.02). A trend was observed in liver samples where pigs fed the plasma heated to 45 °C had increased lipid oxidation compared with pigs fed the plasma either unheated or heated to 100 °C (P = 0.09). DNA damage in the jejunum tended to have a linear relationship with the dietary protein oxidation level (P = 0.07). Even though results suggest dietary oxidized protein did not induce oxidative stress during short-term feeding, differences in performance, gut morphology, and digestibility are likely a result of reduced protein availability.

Short-term variability of pulse pressure and systolic and diastolic time in heart transplant recipients

2000 ◽  
Vol 279 (1) ◽  
pp. H122-H129 ◽  
Author(s):  
Denis Chemla ◽  
Eduardo Aptecar ◽  
Jean-Louis Hébert ◽  
Catherine Coirault ◽  
Daniel Loisance ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Linear Relationship ◽  
Time Domain ◽  
Blood Pressure Variability ◽  
Heart Period ◽  
Transplant Recipients ◽  
Short Term ◽  
Positive Linear Relationship ◽  
Heart Transplant Recipients ◽  
Diastolic Time

In heart transplant recipients (HTR), short-term systolic blood pressure variability is preserved, whereas heart rate variability is almost abolished. Heart period is the sum of left ventricular ejection time (LVET) and diastolic time (DT). In the present time-domain prospective study, we tested the hypothesis that short-term fluctuations in aortic pulse pressure (PP) in HTR were related to fluctuations in LVET. Seventeen male HTR (age 48 ± 6 yr) were studied 16 ± 11 mo after transplantation. Aortic root pressure was obtained over a 15-s period using a micromanometer both at rest ( n = 17) and following the cold pressor test (CPT, n = 14). There was a strong positive linear relationship between beat-to-beat LVET and beat-to-beat PP in all patients at rest and in 13 of 14 patients following CPT (each P < 0.01). The slope of this relationship showed little scatter both at rest (0.34 ± 0.07 mmHg/ms) and following CPT (0.35 ± 0.09 mmHg/ms, P = not significant). Given the essentially fixed heart period, DT varied inversely with LVET. As a result, in 13 of 17 HTR at rest and in 12 of 14 HTR following CPT, there was a negative linear relationship between beat-to-beat PP and DT. In conclusion, our short-term time-domain study demonstrated a strong positive linear relationship between LVET and blood pressure variability in male HTR. We also identified a subgroup of HTR in whom there was a mismatch between PP and DT.

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