The ecology of a natural population of Queensland fruit fly, Dacus tryoni II. The distribution of eggs and its relation to behaviour

1969 ◽  
Vol 17 (2) ◽  
pp. 293 ◽  
Author(s):  
G Pritchard
Keyword(s):  
Visual Cues ◽  
Alternative Hypothesis ◽  
Fruit Fly ◽  
Codling Moth ◽  
Ventral Surface ◽  
Physical Factors ◽  
Experimental Conditions ◽  
Uniform Dispersion ◽  
The Difference ◽  
Egg Limitation

The oviposition of Queensland fruit fly is described and the distribution of eggs within and between fruits is analysed. Olfactory and visual cues direct females to fruit. A brief exploratory phase then follows after which the female applies the ventral surface of her head to areas of fruit surface and then moves forward to probe these same areas with her ovipositor. The female lays her eggs into the fruit either after piercing the cuticle with her ovipositor or through existing holes such as previous oviposition holes or holes made by codling moth larvae. As many as 70% of the eggs laid into hard, shiny fruits were laid into existing holes, but in softer fruits with protuberances over the surface less than 20% were laid in this way. The difference is related to a backward component in the push by the ovipositor, leading to difficulty in piercing hard, smooth unbroken skin. Ovipositions are further grouped on single fruits owing to the favourability of certain areas in relation to such physical factors as wind and illumination. In the laboratory it was not possible under any circumstances to achieve a uniform dispersion of ovipositions when a succession of single females was given the choice of a number of oviposition sites. Contagious distributions were the rule, although randomness of oviposition was exhibited in certain experimental designs. In the field, under natural and experimental conditions, oviposition holes were generally contagiously distributed between fruit. The data offer no support to the hypothesis that oviposition by D. tryoni is affected, in a limiting way, by previous acts of oviposition by other females. An alternative hypothesis for egg limitation at high density, based on aggressive interactions between females on fruit, is suggested.

scholarly journals Potential Pitfalls in Membrane Fouling Evaluation: Merits of Data Representation as Resistance Instead of Flux Decline in Membrane Filtration

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 460
Author(s):  
Bastiaan Blankert ◽  
Bart Van der Bruggen ◽  
Amy E. Childress ◽  
Noreddine Ghaffour ◽  
Johannes S. Vrouwenvelder
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Data Representation ◽  
Strong Impact ◽  
Experimental Conditions ◽  
Permeable Membrane ◽  
Dead End ◽  
Flux Decline ◽  
The Difference ◽  
Filtration Flux

The manner in which membrane-fouling experiments are conducted and how fouling performance data are represented have a strong impact on both how the data are interpreted and on the conclusions that may be drawn. We provide a couple of examples to prove that it is possible to obtain misleading conclusions from commonly used representations of fouling data. Although the illustrative example revolves around dead-end ultrafiltration, the underlying principles are applicable to a wider range of membrane processes. When choosing the experimental conditions and how to represent fouling data, there are three main factors that should be considered: (I) the foulant mass is principally related to the filtered volume; (II) the filtration flux can exacerbate fouling effects (e.g., concentration polarization and cake compression); and (III) the practice of normalization, as in dividing by an initial value, disregards the difference in driving force and divides the fouling effect by different numbers. Thus, a bias may occur that favors the experimental condition with the lower filtration flux and the less-permeable membrane. It is recommended to: (I) avoid relative fouling performance indicators, such as relative flux decline (J/J0); (II) use resistance vs. specific volume; and (III) use flux-controlled experiments for fouling performance evaluation.

scholarly journals Validation of a Method Based on Triglycerides for the Detection of Low Percentages of Hazelnut Oil in Olive Oil by Column Liquid Chromatography

2007 ◽  
Vol 90 (5) ◽  
pp. 1346-1353 ◽  
Author(s):  
Diego L García-González ◽  
María Viera-Macías ◽  
Ramón Aparicio-Ruiz ◽  
Maria T Morales ◽  
Ramón Aparicio
Keyword(s):  
Liquid Chromatography ◽  
Olive Oil ◽  
Carbon Number ◽  
Hazelnut Oil ◽  
Equivalent Carbon Number ◽  
Experimental Conditions ◽  
Mathematical Algorithm ◽  
Relative Standard ◽  
Triglyceride Content ◽  
The Difference

Abstract The difference between theoretical and empirical triglyceride content is a powerful tool to detect the presence of any vegetable oil in olive oil. The current drawback of the method is the separation between equivalent carbon number ECN42 compounds, which affects the reliability of the method and, hence, its cutoff limit. The determination of the triglyceride profile by liquid chromatography using propionitrile as the mobile phase has recently been proposed to improve their quantification, together with a mathematical algorithm whose binary response determines the presence or absence of hazelnut oil. Twenty-one laboratories from 9 countries participated in an interlaboratory study to evaluate the performance characteristics of the whole analytical method. Participants analyzed 12 samples in duplicate, split into 3 intercomparison studies. Statistically significant differences due to the experimental conditions were found in some laboratories, which were detected as outliers by use of Cochran's and Grubbs' tests. The relative standard deviations (RSD) for repeatability and reproducibility were determined following the AOAC Guidelines for Collaborative Studies. The analytical properties of the method were determined by means of the sensitivity (0.86), selectivity (0.94), and reliability (72) for a cutoff limit of 8 (probability 94).

scholarly journals Alpha EEG Frontal Asymmetries during Audiovisual Perception in Cochlear Implant Users

2015 ◽  
Vol 54 (06) ◽  
pp. 500-504 ◽  
Author(s):  
A. G. Maglione ◽  
A. Scorpecci ◽  
P. Malerba ◽  
P. Marsella ◽  
S. Giannantonio ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Alpha Rhythm ◽  
Normal Hearing ◽  
Experimental Conditions ◽  
Audiovisual Perception ◽  
Audiovisual Stimuli ◽  
The Difference ◽  
Eeg Alpha ◽  
The One ◽  
Hearing Children

SummaryObjectives: The aim of the present study is to investigate the variations of the electroencephalographic (EEG) alpha rhythm in order to measure the appreciation of bilateral and unilateral young cochlear implant users during the observation of a musical cartoon. The cartoon has been modified for the generation of three experimental conditions: one with the original audio, another one with a distorted sound and, finally, a mute version.Methods: The EEG data have been recorded during the observation of the cartoons in the three experimental conditions. The frontal alpha EEG imbalance has been calculated as a measure of motivation and pleasantness to be compared across experimental populations and conditions.Results: The EEG frontal imbalance of the alpha rhythm showed significant variations during the perception of the different cartoons. In particular, the pattern of activation of normal-hearing children is very similar to the one elicited by the bilateral implanted patients. On the other hand, results related to the unilateral subjects do not present significant variations of the imbalance index across the three cartoons.Conclusion: The presented results suggest that the unilateral patients could not appreciate the difference in the audio format as well as bilaterally implanted and normal hearing subjects. The frontal alpha EEG imbalance is a useful tool to detect the differences in the appreciation of audiovisual stimuli in cochlear implant patients.

The Role of Organizational Development in Achieving the Competitive Advantage of University of Hail as one of the requirements of The vision of the Kingdom of Saudi Arabia 2030

2021 ◽  
Vol 15 ◽  
pp. 71-82
Author(s):  
Nada Zwayyid Almutairi ◽  
Eman Salah Ibrahim Rizk
Keyword(s):  
Saudi Arabia ◽  
Organizational Development ◽  
Visual Cues ◽  
Kingdom Of Saudi Arabia ◽  
Auditory Cues ◽  
Learning Retention ◽  
Lr Test ◽  
The Difference ◽  
Academic Year

This study explores interactive e-book cues and Information Processing Levels (IPL)’s effectiveness on Learning Retention (LR) and External Cognitive Load (ECL). 117 middle school pupils (MSP) were divided into six experimental groups based on their IPL and cues during the second term of the academic year 2019–2020. Visual Cues (VC)/Audiovisual Cues (VAC) and Auditory Cues (AC)/Audiovisual Cues (VAC) statistically varied in the Ie-book in LR test and ECL scale, same for the average scores when testing the LR in Science for MSP due to the difference between IPL for the DL. There is a statistically significant effect of cue types' interaction in Ie-book with IPL in ECL scale for MSP, at its highest peak in the case of the AVC with DL, followed by the interaction resulting from the VC with DL then AC with SL. Also, cues interaction in Ie-book with IPL immensely affect the LR test for MEP, which is at its highest peak in the case of the AVC with DL. The interactions between (DL–SL) and (AC–VC) seem to equally influence the ELC.

Crucial Effects of Weightlessness on Human Orientation

1993 ◽  
Vol 3 (3) ◽  
pp. 307-314 ◽  
Author(s):  
H. Mittelstaedt ◽  
S. Glasauer
Keyword(s):  
Visual Cues ◽  
Decisive Role ◽  
Experimental Conditions ◽  
Subjective Vertical ◽  
Independent Components ◽  
Human Orientation ◽  
The Mean ◽  
Trunk Tilt

This contribution examines the consequences of two remarkable experiences of subjects in weightlessness, 1) the missing of sensations of trunk tilt and of the respective concomitant reflexes when the head is tilted with respect to the trunk, and 2) the persistence of a perception of “up” and “down,” that is, of the polarity of the subjective vertical (SV) in the absence of, as well as in contradiction to, visual cues. The first disproves that the necessary head-to-trunk coordinate transformation be achieved by adding representations of the respective angles gained by utricles and neck receptors, but corroborates an extant model of cross-multiplication of utricular, saccular, and neck receptor components. The second indicates the existence of force-independent components in the determination of the SV. Although the number of subjects is still small and experimental conditions are not as homogeneous as desired, measurements and/or reports on the ground, in parabolic, and in space flight point to the decisive role of the saccular z-bias, that is, of a difference of the mean resting discharges of saccular units polarized in the rostrad and the caudad (±z-) direction.

The diffusion of 75Se(IV) in Beishan granite – temperature, oxygen condition and ionic strength effects

2018 ◽  
Vol 107 (1) ◽  
pp. 39-54
Author(s):  
Chunli Wang ◽  
Xiaoyu Yang ◽  
Jiangang He ◽  
Fangxin Wei ◽  
Zhong Zheng ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Effective Diffusion ◽  
Aerobic Condition ◽  
Double Layers ◽  
Solution Viscosity ◽  
Formation Factor ◽  
Experimental Conditions ◽  
Beishan Granite ◽  
Oxygen Condition ◽  
The Difference

Abstract To explore the diffusion behavior of 75Se(IV) in Beishan granite (BsG), the influences of temperature, oxygen condition and ionic strength were investigated using the through-diffusion experimental method. The effective diffusion coefficient De of 75Se(IV) in BsG varied from 4.21×10−14 m2/s to 3.19×10−13 m2/s in our experimental conditions, increased with increasing temperature. The formation factor Ff of BsG was calculated to be nearly constant in the range of temperatures investigated, suggesting that the inner structure of BsG had no significant change in the temperature range of 20–55°C. Meanwhile, the De values of 75Se(IV) in BsG under anaerobic condition was significantly larger than that under aerobic condition, which may be attributed to the difference in the sorption characteristics and species distribution of Se and pH values. Moreover, the diffusion of 75Se(IV) was promoted with ionic strength increased from 0.01 M to 0.1 M, and then decreased at 0.5 M, mainly due to the combined effects of reduced double layers with increased ionic strength and increase of the solution viscosity at higher ionic strength.

Neural Processing of Gravito-Inertial Cues in Humans. IV. Influence of Visual Rotational Cues During Roll Optokinetic Stimuli

2003 ◽  
Vol 89 (1) ◽  
pp. 390-400 ◽  
Author(s):  
L. H. Zupan ◽  
D. M. Merfeld
Keyword(s):  
Visual Cues ◽  
Gravitational Force ◽  
Sensory Information ◽  
Inertial Force ◽  
Linear Acceleration ◽  
Otolith Organs ◽  
Optokinetic Stimulation ◽  
The Difference ◽  
The Right ◽  
Roll Tilt

Sensory systems often provide ambiguous information. For example, otolith organs measure gravito-inertial force (GIF), the sum of gravitational force and inertial force due to linear acceleration. However, according to Einstein's equivalence principle, a change in gravitational force due to tilt is indistinguishable from a change in inertial force due to translation. Therefore the central nervous system (CNS) must use other sensory cues to distinguish tilt from translation. For example, the CNS might use dynamic visual cues indicating rotation to help determine the orientation of gravity (tilt). This, in turn, might influence the neural processes that estimate linear acceleration, since the CNS might estimate gravity and linear acceleration such that the difference between these estimates matches the measured GIF. Depending on specific sensory information inflow, inaccurate estimates of gravity and linear acceleration can occur. Specifically, we predict that illusory tilt caused by roll optokinetic cues should lead to a horizontal vestibuloocular reflex compensatory for an interaural estimate of linear acceleration, even in the absence of actual linear acceleration. To investigate these predictions, we measured eye movements binocularly using infrared video methods in 17 subjects during and after optokinetic stimulation about the subject's nasooccipital (roll) axis (60°/s, clockwise or counterclockwise). The optokinetic stimulation was applied for 60 s followed by 30 s in darkness. We simultaneously measured subjective roll tilt using a somatosensory bar. Each subject was tested in three different orientations: upright, pitched forward 10°, and pitched backward 10°. Five subjects reported significant subjective roll tilt (>10°) in directions consistent with the direction of the optokinetic stimulation. In addition to torsional optokinetic nystagmus and afternystagmus, we measured a horizontal nystagmus to the right during and following clockwise (CW) stimulation and to the left during and following counterclockwise (CCW) stimulation. These measurements match predictions that subjective tilt in the absence of real tilt should induce a nonzero estimate of interaural linear acceleration and, therefore, a horizontal eye response. Furthermore, as predicted, the horizontal response in the dark was larger for Tilters ( n = 5) than for Non-Tilters ( n= 12).

scholarly journals Iodination of insulin in aqueous and organic solvents

1969 ◽  
Vol 115 (1) ◽  
pp. 11-18 ◽  
Author(s):  
A. Massaglia ◽  
U. Rosa ◽  
G. Rialdi ◽  
C. A. Rossi
Keyword(s):  
Ethylene Glycol ◽  
Organic Solvents ◽  
Molecular Conformation ◽  
Aqueous Media ◽  
Native Structure ◽  
Experimental Conditions ◽  
Polar Environment ◽  
Polar Area ◽  
The Difference ◽  
A Chain

1. The iodination of insulin was studied under various experimental conditions in aqueous media and in some organic solvents, by measuring separately the uptake of iodine by the four tyrosyl groups and the relative amounts of monoiodotyrosine and di-iodotyrosine that are formed. In aqueous media from pH1 to pH9 the iodination occurs predominantly on the tyrosyl groups of the A chain. Some organic solvents increase the iodine uptake of the B-chain tyrosyl groups. Their efficacy in promoting iodination of Tyr-B-16 and Tyr-B-26 is in the order: ethylene glycol and propylene glycol≃methanol and ethanol>dioxan>8m-urea. 2. It is suggested that each of the four tyrosyl groups in insulin has a different environment: Tyr-A-14 is fully exposed to the solvent; Tyr-A-19 is sterically influenced by the environmental structure, possibly by the vicinity of a disulphide interchain bond; Tyr-B-16 is embedded into a non-polar area whose stability is virtually independent of the molecular conformation; Tyr-B-26 is probably in a situation similar to Tyr-B-16 with the difference that its non-polar environment depends on the preservation of the native structure.

scholarly journals Simplified Orange (Citrus spp.) Production Guide for Small-scale Farmers

2020 ◽  
pp. 23-27
Author(s):  
Hillary M. O. Otieno
Keyword(s):  
Soil Analysis ◽  
Fruit Fly ◽  
Codling Moth ◽  
Water Infiltration ◽  
High Yield ◽  
Small Scale ◽  
Leaf Miners ◽  
Land Preparation ◽  
False Codling Moth ◽  
Small Scale Farmers

Orange production provides both nutritional and financial benefits to farmers across Africa. However, these farmers do not realize the full benefits due to low yields caused by poor agronomic practices currently applied in the region. This guide, therefore, highlights key practices that farmers need to adopt for better yields. Farmers should always follow the best practices right from the selection of a variety to harvesting practices for high yield and better quality fruits to be achieved. Proper land preparation helps in early weed control and improves water infiltration and growth of roots. Weeds should always be kept below economic thresholds to ensure efficiencies in the use of water and nutrient. Like other plants, oranges require proper nutrition for growth and development of big fruits. Both manure and inorganic fertilizers should be applied depending on the availability and cost. Soil analysis helps in determining the rates of application. During production, farmers should scout for pests such as aphids, false codling moth, whiteflies, leaf miners, thrips, fruit fly and common spiral nematode and diseases like Pseudocercospora leaf and fruit spot, Phytophthora spp. and orange fruit scab which are common in the area. These pests cause significant yield losses if not timely controlled. When ready, harvesting of fruits should be careful and gentle without causing injuries.

scholarly journals Optimal minimax rates against non-smooth alternatives

2021 ◽  
Author(s):  
Kohtaro Hitomi ◽  
Masamune Iwasawa ◽  
Yoshihiko Nishiyama
Keyword(s):  
Alternative Hypothesis ◽  
Error Variance ◽  
Smooth Functions ◽  
Engel Curves ◽  
Minimax Rates ◽  
Instrumental Variable Regression ◽  
Bounded Functions ◽  
The Difference ◽  
Set Up ◽  
Minimax Rate

Abstract This study investigates optimal minimax rates for specification testing when the alternative hypothesis is built on a set of non-smooth functions. The set consists of bounded functions that are not necessarily differentiable with no smoothness constraints imposed on their derivatives. In the instrumental variable regression set up with an unknown error variance structure, we find that the optimal minimax rate is n−1/4, where n is the sample size. The rate is achieved by a simple test based on the difference between non-parametric and parametric variance estimators. Simulation studies illustrate that the test has reasonable power against various non-smooth alternatives. The empirical application to Engel curves specification emphasizes the good applicability of the test.

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