The role of intruder behaviour in nestmate recognition by bumble bees (Hymenoptera: Apidae)

1988 ◽  
Vol 66 (12) ◽  
pp. 2847-2851 ◽  
Author(s):  
R. C. Plowright ◽  
G. A. Fuller
Keyword(s):  
Nestmate Recognition ◽  
Bumble Bees ◽  
Series Of Experiments ◽  
The Difference ◽  
Main Effects

A series of experiments on the response of bumble bees to the introduction of bees into their colonies are reported. The two main effects, both of which were statistically significant, were (i) class of intruder (nestmate, alien conspecific, or heterospecific) and (ii) whether or not the intruder was anaesthetized. Significant interactions were also obtained: the difference in response of the resident bees to whether the intruders were conspecific or heterospecific depended also on whether or not the intruders were anaesthetized. The relevance of these results to the possibility that intruders are recognized by their behaviour (as well as their odour) is discussed.

Visual figure–ground discrimination in the honeybee: the role of motion parallax at boundaries

1990 ◽  
Vol 238 (1293) ◽  
pp. 331-350 ◽  
Keyword(s):  
Apparent Motion ◽  
Motion Parallax ◽  
The Other ◽  
Neural Models ◽  
Height Difference ◽  
Sugar Water ◽  
Different Types ◽  
Series Of Experiments ◽  
The Difference

Free flying bees were trained to collect a reward of sugar-water from a structured figure, placed at a randomly varying location on a sheet of transparent Perspex, positioned 5 cm above a structured Background. During subsequent tests, done in the absence of a reward, the bees’ landings on the boundaries of the figure, as well as within the figure and outside it, were recorded. The same bees were also tested with the figure placed directly on the background, thus eliminating the difference in height between the figure and the background. The results of both types of tests were then compared to identify and investigate the cues that bees use to detect a structured figure, when presented over a structured background. The structure of both the figure and the background were varied in a series of experiments, training a fresh group of bees in each experiment. A randomly structured figure presented against a randomly structured background cannot be detected by the bees unless it is raised above the background. A height difference of 2 cm is sufficient to elicit a rate of landings on the figure that is significantly higher than the chance level. The detectability of the figure does not depend upon the shape of the figure or on differences in density between the structures of the figure and the background. Thus, in detecting the raised figure, the only cue used by the bees appears to be the apparent motion of the figure relative to the background. The majority of landings on a raised figure occur at its boundaries. This shows that the visual stimulus that is crucial in detecting the figure is the local discontinuity in apparent motion that occurs at the boundary. We refer to this as ‘boundary parallax ’. In a series of experiments that used a striped background and a variety of structured figures, three different types of boundary parallax were offered to the bees. These were: (i) ‘covering parallax’, at a boundary in which stripes on either side of the boundary are parallel to the boundary; (ii) ‘shearing parallax’, in which stripes on either side are perpendicular to the boundary and (iii) ‘orthogonal parallax’, in which the stripes on one side are perpendicular to those on the other side. The bees performed very well at detecting raised boundaries that offered covering or shearing parallax, despite the fact that such boundaries are not readily discernible on the basis of their static geometry. On the other hand, bees performed poorly in detecting raised boundaries that offered orthogonal parallax, despite the fact that such boundaries are geometrically quite vivid to the human eye. We propose two neural models for the detection of boundary parallax that account for the sensitivity of bees to covering and shearing parallax and their insensitivity to orthogonal parallax.

The role of differential phase contrast in electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 176-177
Author(s):  
E.M. Waddell ◽  
J.N. Chapman ◽  
R.P. Ferrier
Keyword(s):  
Phase Contrast ◽  
Practical Method ◽  
Position Vector ◽  
Differential Phase ◽  
Pure Phase ◽  
Differential Phase Contrast ◽  
The Difference ◽  
Image Position ◽  
First Moment

Dekkers and de Lang (1977) have discussed a practical method of realising differential phase contrast in a STEM. The method involves taking the difference signal from two semi-circular detectors placed symmetrically about the optic axis and subtending the same angle (2α) at the specimen as that of the cone of illumination. Such a system, or an obvious generalisation of it, namely a quadrant detector, has the characteristic of responding to the gradient of the phase of the specimen transmittance. In this paper we shall compare the performance of this type of system with that of a first moment detector (Waddell et al.1977).For a first moment detector the response function R(k) is of the form R(k) = ck where c is a constant, k is a position vector in the detector plane and the vector nature of R(k)indicates that two signals are produced. This type of system would produce an image signal given bywhere the specimen transmittance is given by a (r) exp (iϕ (r), r is a position vector in object space, ro the position of the probe, ⊛ represents a convolution integral and it has been assumed that we have a coherent probe, with a complex disturbance of the form b(r-ro) exp (iζ (r-ro)). Thus the image signal for a pure phase object imaged in a STEM using a first moment detector is b2 ⊛ ▽ø. Note that this puts no restrictions on the magnitude of the variation of the phase function, but does assume an infinite detector.

The Role of Positive and Negative Affectivity in Healthy and Unhealthy Work-Related Behavior and Experiences

2019 ◽  
Vol 26 (2) ◽  
pp. 56-67 ◽  
Author(s):  
Hanna Hofmann ◽  
Carl-Walter Kohlmann
Keyword(s):  
Negative Affectivity ◽  
Coping Behavior ◽  
Common Method ◽  
Positive Affectivity ◽  
Work Related ◽  
Teacher Students ◽  
And Behaviors ◽  
Main Effects ◽  
Positive And Negative Affectivity

Abstract. Positive affectivity (PA) and negative affectivity (NA) are basic traits that affect work-related perceptions and behaviors and should be considered in any assessment of these variables. A quite common method to assess healthy or unhealthy types of work-related perceptions and behaviors is the questionnaire on Work-Related Coping Behavior and Experience Patterns (WCEP). However, the association of PA and NA with WCEP remained unclear. In a sample of teachers, physiotherapists, and teacher students ( N = 745; Mage = 35.07, SD = 12.49; 78% females), we aimed to identify the relevance of these basic traits. After controlling for age, gender, and type of occupation, we found main effects of PA and NA, with the specific combination of PA and NA being decisive for predicting the assignment to a WCEP type. The results highlight the need to include PA and NA in future assessments with the WCEP questionnaire.

On the Role of Transferrin in 67Ga Uptake by Tumor Cells

1988 ◽  
Vol 27 (04) ◽  
pp. 151-153
Author(s):  
P. Thouvenot ◽  
F. Brunotte ◽  
J. Robert ◽  
L. J. Anghileri
Keyword(s):  
Specific Binding ◽  
Subcellular Fractionation ◽  
Animal Blood ◽  
Tumor Bearing ◽  
Cell Structures ◽  
The Difference ◽  
Sarcoma Cells ◽  
In Vitro Uptake

In vitro uptake of 67Ga-citrate and 59Fe-citrate by DS sarcoma cells in the presence of tumor-bearing animal blood plasma showed a dramatic inhibition of both 67Ga and 59Fe uptakes: about ii/io of 67Ga and 1/5o of the 59Fe are taken up by the cells. Subcellular fractionation appears to indicate no specific binding to cell structures, and the difference of binding seems to be related to the transferrin chelation and transmembrane transport differences

The role of copper ions in hydrogen peroxide bleaching: Their origin, removal, and effect on pulp quality

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO
Keyword(s):  
Hydrogen Peroxide ◽  
Copper Ions ◽  
Peroxide Bleaching ◽  
Metals Removal ◽  
Peroxide Decomposition ◽  
Equipment Corrosion ◽  
And Performance ◽  
And Control ◽  
Main Effects

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.

REFLECTION COEFFICIENT OF AN ELECTROMAGNETIC WAVE IN CONDUCTIVE MEDIA

2018 ◽  
pp. 100-106
Author(s):  
M. S. Sudakova ◽  
M. L. Vladov ◽  
M. R. Sadurtdinov
Keyword(s):  
Reflection Coefficient ◽  
Ground Penetrating Radar ◽  
Electromagnetic Waves ◽  
Water Contamination ◽  
Survey Design ◽  
Direct And Inverse Problems ◽  
The Difference ◽  
Ground Penetrating ◽  
Ideal Dielectric

Within the ground penetrating radar bandwidth the medium is considered to be an ideal dielectric, which is not always true. Electromagnetic waves reflection coefficient conductivity dependence showed a significant role of the difference in conductivity in reflection strength. It was confirmed by physical modeling. Conductivity of geological media should be taken into account when solving direct and inverse problems, survey design planning, etc. Ground penetrating radar can be used to solve the problem of mapping of halocline or determine water contamination.

Speculative Realism and Science Fiction

2017 ◽  
Author(s):  
Brian Willems
Keyword(s):  
Science Fiction ◽  
Identity Formation ◽  
Cormac Mccarthy ◽  
Doris Lessing ◽  
Speculative Realism ◽  
Neil Gaiman ◽  
The World ◽  
The Difference ◽  
Quentin Meillassoux

A human-centred approach to the environment is leading to ecological collapse. One of the ways that speculative realism challenges anthropomorphism is by taking non-human things to be as valid objects of investivation as humans, allowing a more responsible and truthful view of the world to take place. Brian Willems uses a range of science fiction literature that questions anthropomorphism both to develop and challenge this philosophical position. He looks at how nonsense and sense exist together in science fiction, the way in which language is not a guarantee of personhood, the role of vision in relation to identity formation, the difference between metamorphosis and modulation, representations of non-human deaths and the function of plasticity within the Anthropocene. Willems considers the works of Cormac McCarthy, Paolo Bacigalupi, Neil Gaiman, China Miéville, Doris Lessing and Kim Stanley Robinson are considered alongside some of the main figures of speculative materialism including Graham Harman, Quentin Meillassoux and Jane Bennett.

On the Use of Quantum Thermal Bath in Unimolecular Fragmentation Simulations

2019 ◽  
Author(s):  
Riccardo Spezia ◽  
Hichem Dammak
Keyword(s):  
Degrees Of Freedom ◽  
Molecular Simulations ◽  
Zero Point ◽  
Thermal Bath ◽  
Unimolecular Dissociation ◽  
Point Energy ◽  
Rotational Degrees Of Freedom ◽  
The Difference ◽  
Nuclear Effects

<div> <div> <div> <p>In the present work we have investigated the possibility of using the Quantum Thermal Bath (QTB) method in molecular simulations of unimolecular dissociation processes. Notably, QTB is aimed in introducing quantum nuclear effects with a com- putational time which is basically the same as in newtonian simulations. At this end we have considered the model fragmentation of CH4 for which an analytical function is present in the literature. Moreover, based on the same model a microcanonical algorithm which monitor zero-point energy of products, and eventually modifies tra- jectories, was recently proposed. We have thus compared classical and quantum rate constant with these different models. QTB seems to correctly reproduce some quantum features, in particular the difference between classical and quantum activation energies, making it a promising method to study unimolecular fragmentation of much complex systems with molecular simulations. The role of QTB thermostat on rotational degrees of freedom is also analyzed and discussed. </p> </div> </div> </div>

«Имперский синдром»: концепция османского халифата на Ближнем Востоке и в Южной Азии (первая четверть XX в.)

2019 ◽  
Author(s):  
S.A. Kirillina ◽  
A.L. Safronova ◽  
V.V. Orlov
Keyword(s):  
Middle East ◽  
South Asia ◽  
South Asian ◽  
Political Role ◽  
The Social ◽  
The Difference ◽  
Aspect Interaction ◽  
Muhammad Rashid Rida ◽  
Political Actions

Аннотация В статье изучены общие и специфические черты идейных воззрений, пропагандистской риторики и политических действий представителей халифатистского движения на Ближнем Востоке и в Южной Азии. В ретроспективном ключе прослеживается эволюция представлений о сущности и необходимости возрождения института халифата в трудах исламских идеологов, реформаторов и политиков Джамал ад-Дина ал-Афгани, Абд ар-Рахмана ал-Кавакиби, Мухаммада Рашида Риды, Абул Калама Азада. Внимание авторов сосредоточено на общественно-политических дискуссиях 2030-х годов XX столетия, а также на повестке дня халифатистских конгрессов и конференций этого периода. На них вырабатывались первые представления современников о пост-османском формате мусульманского единства и идейно-политической роли будущего халифата. Авторы демонстрируют различие между моделями реакции мусульман Ближнего Востока и Южной Азии на упразднение османского халифата республиканским руководством Турции. Установлена многоаспектная взаимосвязь между халифатистскими ценностями, проосманскими настроениями и формами самоотождествления, которые сложились в арабских и южноазиатских обществах. Отдельно намечено соотношение между подъемом халифатистских настроений и радикализацией антиколониальных действий мусульман Индостана.Abstract The article deals with analysis of common and specific features of ideas, propaganda, rhetoric and political actions taken by representatives of the movement for defense of the Caliphate in the Middle East and South Asia. The retrospection showing the transformation of conception of the Caliphate and the necessity of its revival in the works of eminent ideologists and politicians of the Muslim world Jamal al-Din al-Afghani, Abd al-Rahman al-Kawakibi, Muhammad Rashid Rida and Abul Kalam Azad, is also given in the article. The authors also focus on the social and political discussions of the 1920s 1930s, as well as on the agenda of Caliphatist congresses and conferences of this period. They helped to elaborate the early representations of post-Ottoman pattern of the Muslim unity and the ideological and political role of the future Caliphate. The authors demonstrate the difference between the forms of reaction of Muslims in the Middle East and South Asia to the repudiation of the Caliphate by the Republican leaders of Turkey. The article establishes a multi-aspect interaction between the Caliphatist values and forms of self-identification, emerged in Arab and South Asian societies. The correlation between the rise of Caliphatist attitudes and radicalization of anti-colonial actions of South Asian Muslims is also outlined.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

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