Change of Phototropic and Geotropic Signs in Daphnia Induced by Changes of Light Intensity

1930 ◽  
Vol 7 (2) ◽  
pp. 109-131 ◽  
Author(s):  
G. L. CLARKE
Keyword(s):  
Light Intensity ◽  
Latent Period ◽  
Daphnia Pulex ◽  
Great Majority ◽  
Absolute Intensity ◽  
Rate Of Change ◽  
Intensity Change ◽  
The Difference ◽  
The Individual ◽  
Secondary Signs

1. A method is described for studying the responses of Daphnia to changes of light intensity with special attention to the behaviour of the individual and to the avoidance of "shock" effects. The types of apparatus used provide for rigid control of the temperature, for illumination from any direction, and for an adjustable rate of change of the light intensity by means of a chemical rheostat. 2. The great majority of Daphnia magna and Daphnia pulex were found to be primarily negatively phototropic and positively geotropic. That is, they always exhibited those tropistic signs under constant conditions of illumination. 3. A reduction of the light intensity causes a temporary reversal of the tropism signs. The secondary signs thus produced are positive phototropism and negative geotropism. 4. The presence of both phototropic and geotropic forces is proved by experiments in which illumination is (1) from one side, (2) from beneath, and (3) from two opposing sides or from above and below simultaneously. In these tests and in others in which very slow and very fast rates of dimming are used the phototropic and geotropic forces are resolved, antagonised, and neutralised in succession. The responses of the Daphnia indicate that there are two types of animals which exhibit exactly the same tropisms, but in one type phototropism is the stronger while in the other geotropism is the stronger. 5. In this material it was found that the temporary secondary tropistic signs persisted only a few minutes while the primary signs persisted for hours, although this effect was somewhat less marked in weak light or in darkness. 6. The difference between "time-change" and "place-change" of light in tensity is pointed out. Daphnia is stimulated by both types of change if the rate of change is sufficiently great. 7. That photosensitive animals are stimulated to respond to changes in the intensity of light only and are merely orientated by the direction of the light is shown in the work of previous, investigators as well as in this paper. The rigidity of this mechanism is indicated by experiments in which the light is graded in intensity at right angles to its direction and in which the light is rendered converging and diverging by a lens. 8. Evidence is given for believing that there is no "absolute optimum" light intensity for Daphnia but that a "relative optimum" exists which is the intensity to which the animals are adapted at the moment. 9. The interval between the inception of the reduction of the light intensity and the beginning of swimming movements in response is called the latent period. The faster the rate of dimming, the shorter is the duration of the latent period. A minimum, amount of intensity change is required to produce any response, at any speed, but beyond that the slower the rate of dimming, the greater is the amount of change required and hence the lower is the absolute intensity at which the response takes place. Ordinarily, the response is maximal in respect to both rate and magnitude. 10. Fatigue will interfere with experimentation unless guarded against. 11. Specimens of Daphinia with reversed primary signs gain temporary secondary signs following an increase of light intensity; otherwise they behave like the more usual forms. 12. The possibility that the processes of adaptation in Daphnia may account for the photic responses observed is discussed. Support for this theory is derived from the fact that it is possible to dim the light over a given range at such a slow rate that no response is produced.

Quantitative Aspects of the Change of Phototropic Sign in Daphnia

1932 ◽  
Vol 9 (2) ◽  
pp. 180-211
Author(s):  
GEORGE L. CLARKE
Keyword(s):  
Light Intensity ◽  
Bright Light ◽  
Absolute Intensity ◽  
Minimum Length ◽  
Period 2 ◽  
Table Xiii ◽  
Duration Of Response ◽  
The Difference ◽  
The Individual ◽  
Periodic Changes

1. A quantitative study of the responses of Daphnia magna to light was made with the use of an experimental trough illuminated horizontally through one end by a uniform beam of light. The intensity of light was changed by shifting the position of a neutral glass "wedge" interposed in the beam of light. 2. The difference in the position of Daphnia when positively phototropic and when negatively phototropic is a difference in the postural angle at which the antennae are held, and not a difference in the direction of orientation of the whole organism--the animal's back being toward the light under all circumstances. 3. The primary sign of phototropism is not altered according to the absolute intensity of the light, but is affected by (1) the age of the individual, (2) the temperature of the water, and (3) the condition of the culture medium. Sometimes a "spontaneous" change in the primary sign of phototropism occurs. 4. The occasional movements observed to occur in the direction opposite to that of the primary sign of phototropism appear to be essentially periodic in respect to their times of inception and their duration. These periodic movements of Daphnia are not due to recurring periods of increased or of decreased activity, but probably represent periodic changes in the underlying photic mechanism. 5. "Variability" of the responses of Daphnia to successive identical tests gives evidence of being fundamentally periodic. A system of experimentation was devised to eliminate the error due to this variability, in so far as this was possible. 6. It was found that the rate and the magnitude of the change of illumination must rise above a certain threshold to be effective in causing a reversal of phototropic sign. A minimum length of exposure to bright light before the test is made is also necessary. 7. The relations of (1) length of the latent period, (2) speed of response, (3) magnitude of response, and (4) duration of response to (a) amount of reduction of light intensity, (b) duration of previous exposure to light, (c) duration of previous sojourn in dark, and (d) temperature of the water, were investigated, and the results have been summarised in Table XIII. 8. My observations are consistent with Ewald's conclusions that orientation of Daphnia is based on a mechanism which is entirely distinct from that responsible for the other three aspects of phototropism, namely (1) persistent phototropic swimming under any constant illumination, (2) periodic changes of phototropic sign under constant low illumination, and (3) reversal of phototropism produced by changes of light intensity. 9. It is shown that these other aspects of phototropism of Daphnia could be accounted for by one mechanism of excitation, if it were photoreversible and properly controlled. A theory is proposed that this mechanism is a reversible photochemical system such as that used by Hecht. The theoretical requirements of the mechanism would be fulfilled on the assumption (1) that equilibrium in the system would result in the maintenance of the persistent primary sign of phototropism, and (2) that the upsetting of this equilibrium would result in the production of the secondary signs. Upsetting of the equilibrium by some internal rhythmic process and by changes of illumination would account for periodic phototropic movements and for induced reversals of phototropic sign, respectively. 10. The results of the experiments on the photic responses have been reviewed in the terms of the proposed theory, and it is found that the evidence strongly supports the hypothesis that a reversible photochemical system is the basis for these aspects of the phototropism of Daphnia.

Abstract 194: Rosuvastatin Reduces Progression of Carotid Atherosclerosis within 12 Months of Treatment: The METEOR Trial

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Michiel L Bots ◽  
Joel S Raichlen ◽  
Gregory W Evans ◽  
Mike K Palmer ◽  
Daniel H O’Leary ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Controlled Trial ◽  
Intima Media Thickness ◽  
Carotid Intima Media Thickness ◽  
Rate Of Change ◽  
Double Blind ◽  
Atherosclerosis Progression ◽  
Media Thickness ◽  
The Difference ◽  
The Individual

Background: In several statin trials, vascular event rates for treatment groups begin to separate 1 year after commencement of treatment. For atherosclerosis progression, the temporal sequence of the effect has not been defined. We sought to determine the earliest time point at which significant differences in atherosclerosis progression rates were detectable after initiation of statin therapy using data from the METEOR trial (Measuring Effects on intima media Thickness: an Evaluation Of Rosuvastatin). Methods: METEOR was a double-blind, randomized, placebo-controlled trial among 984 low risk subjects, which studied the effect of LDL lowering with 40 mg rosuvastatin on the rate of change in carotid intima media thickness (CIMT) over time. Ultrasound assessments were made at 12 carotid artery sites at baseline and every 6 months up to two years. In these analyses, the data were cut at 6 months, 1 year, and 18 months, and compared with analysis of all data at 2 years, using the same statistical method. Results: The difference in rate of maximum CIMT progression for all carotid artery sites (primary endpoint - near and far walls of the left and right common carotid artery [CCA], carotid bulb and internal carotid artery) between the rosuvastatin and placebo groups was apparent 6 months after baseline (0.0023 mm/yr and 0.0106 mm/yr, respectively p =0.36). After 12 months CIMT progression rates were significantly different between groups: 0.0032 mm/yr and 0.0133 mm/yr (p=0.049). This divergence grew with further follow-up: − 0.0009 mm/yr and 0.0131 mm/yr after 18 months (p<0.0001), and − 0.0014 mm/yr and 0.0131 mm/yr after 24 months of treatment (p<<178>0.0001). For the individual carotid artery segments, significant differences were seen at 12 months for the mean CIMT of the CCA, and at 18 months for the maximum CIMT of the bulb and the CCA. Conclusion: Aggressive LDL lowering with rosuvastatin exerts its beneficial effect on atherosclerosis during the first year of treatment, which parallels the timing of event rate reduction seen in clinical trials. These findings suggest that, in trials examining the effects of treatment on CIMT progression, a duration of 12 months may be adequate, given sufficient sample size, high precision of measurements, and treatment effect.

Empirical Study On Attributes Leading To Satisfaction Among Bank Customer

2019 ◽  
Vol 118 (7) ◽  
pp. 101-110
Author(s):  
Ms.U.Sakthi Veeralakshmi ◽  
Dr.G. Venkatesan
Keyword(s):  
Service Quality ◽  
Behavioral Intention ◽  
Banking Sector ◽  
Positive Impact ◽  
Quality Performance ◽  
Public And Private ◽  
The Difference ◽  
The Individual ◽  
Private Banking ◽  
Service Gap

This research aims at measuring the service quality in public and private banking sector and identifying its relationship to customer satisfaction and behavioral intention. The study was conducted among 500 bank customers by using revised SERVQUAL instrument with 26 items. Behavioral intention of the customers was measured by using the behavioral intention battery. The researcher has used a seven point likert scaling to measure the expected and perceived service quality (performance) and the behavioral intention of the customer. The instrument was selected as the most reliable device to measure the difference-score conceptualization. It is used to evaluate service gap between expectation and perception of service quality. Modifications are made on the SERVQUAL instrument to make it specific to the Banking sector. Questions were added to the instrument like Seating space for waiting (Tangibility), Parking space in the Bank (Tangibility), Variety of products / schemes available (Tangibility), Banks sincere steps to handling Grievances of the customers (Responsiveness). The findings of the study revealed that the customer’s perception (performance) is lower than expectation of the service quality rendered by banks. Responsiveness and Assurance SQ dimensions were the most important dimensions in service quality scored less SQ gap. The study concluded that the individual service quality dimensions have a positive impact on Overall Satisfaction.

THE SUBJECT FIELD OF INSTITUTIONAL EDUCATION: THE SENSE AND PROSPECTS OF DEVELOPMENT IN UKRAINE

2020 ◽  
pp. 25-38
Author(s):  
Irina Mordous
Keyword(s):  
Decisive Role ◽  
Subject Field ◽  
National Education ◽  
Progressive Development ◽  
Separate Area ◽  
Economic Transformations ◽  
The Difference ◽  
The Individual ◽  
Political Economic

The development of modern civilization attests to its decisive role in the progressive development of institutions. They identified the difference between Western civilization and the rest of the world. Confirmation of the institutional advantages of the West was its early industrialization. The genesis and formation of institutionalism in its ideological and conceptualmethodological orientation occurs as a process alternative to neoclassic in the context of world heterodoxia, which quickly spread in social science. Highlighting institutional education as a separate area of sociocultural activity is determined by the factor of differentiation of institutional theory as a whole. A feature of institutional education is its orientation toward the individual and his/her transformation into a personality. The content of institutional education is revealed through the analysis of the institution, which includes a set of established customs, traditions, ways of thinking, behavioral stereotypes of individuals and social groups. The dynamics of socio-political, economic transformations in Ukraine requires a review of the foundations of national education and determination of the prospects for its development in the 21st century in the context of institutionalism.

Quantitative indicators of air traffic controllers’ attitude to the danger of errors

2020 ◽  
pp. 68-78
Author(s):  
O. M. Reva ◽  
V. V. Kamyshin ◽  
S. P. Borsuk ◽  
V. A. Shulhin ◽  
A. V. Nevynitsyn
Keyword(s):  
Human Factor ◽  
Differential Method ◽  
Air Traffic ◽  
Professional Activity ◽  
Aviation Accidents ◽  
Air Traffic Controllers ◽  
The Difference ◽  
Level Of Significance ◽  
The Individual ◽  
High Level

The negative and persistent impact of the human factor on the statistics of aviation accidents and serious incidents makes proactive studies of the attitude of “front line” aviation operators (air traffic controllers, flight crewmembers) to dangerous actions or professional conditions as a key component of the current paradigm of ICAO safety concept. This “attitude” is determined through the indicators of the influence of the human factor on decision-making, which also include the systems of preferences of air traffic controllers on the indicators and characteristics of professional activity, illustrating both the individual perception of potential risks and dangers, and the peculiarities of generalized group thinking that have developed in a particular society. Preference systems are an ordered (ranked) series of n = 21 errors: from the most dangerous to the least dangerous and characterize only the danger preference of one error over another. The degree of this preference is determined only by the difference in the ranks of the errors and does not answer the question of how much time one error is more dangerous in relation to another. The differential method for identifying the comparative danger of errors, as well as the multistep technology for identifying and filtering out marginal opinions were applied. From the initial sample of m = 37 professional air traffic controllers, two subgroups mB=20 and mG=7 people were identified with statisti-cally significant at a high level of significance within the group consistency of opinions a = 1%. Nonpara-metric optimization of the corresponding group preference systems resulted in Kemeny’s medians, in which the related (middle) ranks were missing. Based on these medians, weighted coefficients of error hazards were determined by the mathematical prioritization method. It is substantiated that with the ac-cepted accuracy of calculations, the results obtained at the second iteration of this method are more ac-ceptable. The values of the error hazard coefficients, together with their ranks established in the preference systems, allow a more complete quantitative and qualitative analysis of the attitude of both individual air traffic controllers and their professional groups to hazardous actions or conditions.

Quality-of-Life Measurement in Advanced Cancer: Assessing the Individual

1999 ◽  
Vol 17 (11) ◽  
pp. 3603-3611 ◽  
Author(s):  
Dympna Waldron ◽  
Ciaran A. O'Boyle ◽  
Michael Kearney ◽  
Michael Moriarty ◽  
Desmond Carney
Keyword(s):  
Quality Of Life ◽  
Advanced Cancer ◽  
Internal Validity ◽  
Semistructured Interview ◽  
Incurable Cancer ◽  
Life Measurement ◽  
The Difference ◽  
The Individual ◽  
Very High

PURPOSE: Despite the increasing importance of assessing quality of life (QoL) in patients with advanced cancer, relatively little is known about individual patient's perceptions of the issues contributing to their QoL. The Schedule for the Evaluation of Individual Quality of Life (SEIQoL) and the shorter SEIQoL–Direct Weighting (SEIQoL-DW) assess individualized QoL using a semistructured interview technique. Here we report findings from the first administration of the SEIQoL and SEIQoL-DW to patients with advanced incurable cancer. PATIENTS AND METHODS: QoL was assessed on a single occasion using the SEIQoL and SEIQoL-DW in 80 patients with advanced incurable cancer. RESULTS: All patients were able to complete the SEIQoL-DW, and 78% completed the SEIQoL. Of a possible score of 100, the median QoL global score was as follows: SEIQoL, 61 (range, 24 to 94); SEIQoL-DW, 60.5 (range, 6 to 95). Psychometric data for SEIQoL indicated very high levels of internal consistency (median r = .90) and internal validity (median R2 = 0.88). Patients' judgments of their QoL were unique to the individual. Family concerns were almost universally rated as more important than health, the difference being significant when measured using the SEIQoL-DW (P = .002). CONCLUSION: Patients with advanced incurable cancer were very good judges of their QoL, and many patients rated their QoL as good. Judgments were highly individual, with very high levels of consistency and validity. The primacy given to health in many QoL questionnaires may be questioned in this population. The implications of these findings are discussed with regard to clinical assessment and advance directives.

scholarly journals Nondestructive Detection of the Gel State of Preserved Eggs Based on Dielectric Impedance

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 394
Author(s):  
Cheng-Han Li ◽  
Chun-Hung Hsieh ◽  
Cheng-Chu Hung ◽  
Ching-Wei Cheng
Keyword(s):  
Decay Rate ◽  
Mechanical Vibration ◽  
Scientific Basis ◽  
Nondestructive Method ◽  
Inspection System ◽  
Nyquist Diagram ◽  
Detection Technology ◽  
The Difference ◽  
The Individual

After completing the production of preserved eggs, traditionally, the degree of gelling is judged by allowing workers to tap the preserved eggs with their fingers and sense the resulting oscillations. The amount of oscillation is used for the quality classification. This traditional method produces varying results owing to the differences in the sensitivity of the individual workers, who are not objective. In this study, dielectric detection technology was used to classify the preserved eggs nondestructively. The impedance in the frequency range of 2–300 kHz was resolved into resistance and reactance, and was plotted on a Nyquist diagram. Next, the diagram curve was fitted in order to obtain the equivalent circuit, and the difference in the compositions of the equivalent circuits corresponding to gelled and non-gelled preserved eggs was analyzed. A preserved egg can be considered an RLC series circuit, and its decay rate is consistent with the decay rate given by mechanical vibration theory. The Nyquist diagrams for the resistance and reactance of preserved eggs clearly showed that the resistance and reactance of gelled and non-gelled eggs were quite different, and the classification of the eggs was performed using Bayesian network (BN). The results showed that a BN classifier with two variables, i.e., resistance and reactance, can be used to classify preserved eggs as gelled or non-gelled, with an accuracy of 81.0% and a kappa value of 0.62. Thus, a BN classifier based on resistance and reactance demonstrates the ability to classify the quality of preserved egg gel. This research provides a nondestructive method for the inspection of the quality of preserved egg gel, and provides a theoretical basis for the development of an automated preserved egg inspection system that can be used as the scientific basis for the determination of the quality of preserved eggs.

Canons to the Left of Him: Brevard Childs, his Critics, and the Future of Old Testament Theology

1997 ◽  
Vol 50 (1) ◽  
pp. 1-38 ◽  
Author(s):  
Iain Provan
Keyword(s):  
Old Testament ◽  
18Th Century ◽  
Biblical Theology ◽  
Point Of View ◽  
The Bible ◽  
The Difference ◽  
Probable Origin ◽  
The Individual ◽  
The Relationship ◽  
The Church

It is well known that the seeds from which the modern discipline of OT theology grew are already found in 17th and 18th century discussion of the relationship between Bible and Church, which tended to drive a wedge between the two, regarding canon in historical rather than theological terms; stressing the difference between what is transient and particular in the Bible and what is universal and of abiding significance; and placing the task of deciding which is which upon the shoulders of the individual reader rather than upon the church. Free investigation of the Bible, unfettered by church tradition and theology, was to be the way ahead. OT theology finds its roots more particularly in the 18th century discussion of the nature of and the relationship between Biblical Theology and Dogmatic Theology, and in particular in Gabler's classic theoreticalstatementof their nature and relationship. The first book which may strictly be called an OT theology appeared in 1796: an historical discussion of the ideas to be found in the OT, with an emphasis on their probable origin and the stages through which Hebrew religious thought had passed, compared and contrasted with the beliefs of other ancient peoples, and evaluated from the point of view of rationalistic religion. Here we find the unreserved acceptance of Gabler's principle that OT theology must in the first instance be a descriptive and historical discipline, freed from dogmatic constraints and resistant to the premature merging of OT and NT — a principle which in the succeeding century was accepted by writers across the whole theological spectrum, including those of orthodox and conservative inclination.

LONG‐TIME RESPONSE PREDICTED BY EXACT ELASTIC RAY THEORY

Geophysics ◽  
1965 ◽  
Vol 30 (3) ◽  
pp. 363-368 ◽  
Author(s):  
T. W. Spencer
Keyword(s):  
Formal Solution ◽  
Intermediate Stage ◽  
Time Limit ◽  
Time Interval ◽  
Individual Response ◽  
Axially Symmetric ◽  
Long Time ◽  
The Difference ◽  
The Individual ◽  
Significant Figures

The formal solution for an axially symmetric radiation field in a multilayered, elastic system can be expanded in an infinite series. Each term in the series is associated with a particular raypath. It is shown that in the long‐time limit the individual response functions produced by a step input in particle velocity are given by polynomials in odd powers of the time. For rays which suffer m reflections, the degree of the polynomials is 2m+1. The total response is obtained by summing all rays which contribute in a specified time interval. When the rays are selected indiscriminately, the difference between the magnitude of the partial sum at an intermediate stage of computation and the magnitude of the correct total sum may be greater than the number of significant figures carried by the computer. A prescription is stated for arranging the rays into groups. Each group response function varies linearly in the long‐time limit and goes to zero when convolved with a physically realizable source function.

DOES TRUST PROMOTE ENTREPRENEURSHIP IN A DEVELOPING COUNTRY?

2018 ◽  
Vol 63 (05) ◽  
pp. 1385-1403 ◽  
Author(s):  
KITAE SOHN ◽  
ILLOONG KWON
Keyword(s):  
Developing Countries ◽  
Property Rights ◽  
Least Squares ◽  
Developing Country ◽  
Ordinary Least Squares ◽  
Community Level ◽  
Two Stage ◽  
The Us ◽  
The Difference ◽  
The Individual

Trust was found to promote entrepreneurship in the US. We investigated whether this was true in a developing country, Indonesia. We failed to replicate this; this failure was true whether trust was estimated at the individual or community level or whether ordinary least squares (OLS) or two stage least squares (2SLS) was employed. We reconciled the difference between our results and those for the US by arguing that the weak enforcement of property rights in developing countries and the consequent hold-up problem make it more efficient for entrepreneurs to produce generic goods than relationship-specific goods—producing generic goods does not depend on trust.

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