scholarly journals Honeybee navigation: following routes using polarized-light cues

2011 ◽  
Vol 366 (1565) ◽  
pp. 703-708 ◽  
Author(s):  
P. Kraft ◽  
C. Evangelista ◽  
M. Dacke ◽  
T. Labhart ◽  
M. V. Srinivasan
Keyword(s):  
Apis Mellifera ◽  
Food Source ◽  
Polarized Light ◽  
Light Illumination ◽  
Directional Information ◽  
First Time ◽  
Behavioural Evidence ◽  
Do So

While it is generally accepted that honeybees ( Apis mellifera ) are capable of using the pattern of polarized light in the sky to navigate to a food source, there is little or no direct behavioural evidence that they actually do so. We have examined whether bees can be trained to find their way through a maze composed of four interconnected tunnels, by using directional information provided by polarized light illumination from the ceilings of the tunnels. The results show that bees can learn this task, thus demonstrating directly, and for the first time, that bees are indeed capable of using the polarized-light information in the sky as a compass to steer their way to a food source.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

In the Labyrinth

2017 ◽  
Author(s):  
Andrew McNeillie
Keyword(s):  
The Right ◽  
First Time ◽  
Do So

It is now widely acknowledged, and far beyond Ireland, that Tim Robinson’s two volumes jointly known as Stones of Aran (‘Pilgrimage’ and ‘Labyrinth’) are modern classics, exemplary in every way of how to write about place and to do so with a formal, literary accomplishment that more than earns the right to nod at Ruskin’s own classic. In 2012, Robinson went back to Árainn, the largest of the three islands, for the first time in nearly ten years. He did so at the urging of Andrew McNeillie, with whom he spent two and a half days revisiting old haunts. This chapter makes account of the occasion and uses, in the process, a unique document provided by Robinson as an experiment in annotating his work. This prompts McNeillie to investigate some of his own annotations and footnotes to Aran.

Reconstituting the International, 1918–1923

2017 ◽  
Author(s):  
Talbot C. Imlay
Keyword(s):  
Seismic Events ◽  
Great War ◽  
Bolshevik Revolution ◽  
Meaning And Purpose ◽  
Post War ◽  
The Impact ◽  
First Time ◽  
The Great War ◽  
Do So ◽  
Lengthy Process

This chapter examines the post-war efforts of European socialists to reconstitute the Socialist International. Initial efforts to cooperate culminated in an international socialist conference in Berne in February 1919 at which socialists from the two wartime camps met for the first time. In the end, however, it would take four years to reconstitute the International with the creation of the Labour and Socialist International (LSI) in 1923. That it took so long to do so is a testimony to the impact of the Great War and to the Bolshevik revolution. Together, these two seismic events compelled socialists to reconsider the meaning and purpose of socialism. The search for answers sparked prolonged debates between and within the major parties, profoundly reconfiguring the pre-war world of European socialism. One prominent stake in this lengthy process, moreover, was the nature of socialist internationalism—both its content and its functioning.

scholarly journals Breast Cancer Cell Re-Dissemination from Lung Metastases—A Mechanism for Enhancing Metastatic Burden

2021 ◽  
Vol 10 (11) ◽  
pp. 2340
Author(s):  
Lucia Borriello ◽  
John Condeelis ◽  
David Entenberg ◽  
Maja H. Oktay
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Metastatic Disease ◽  
Breast Cancer Cells ◽  
Lung Metastases ◽  
Primary Tumors ◽  
Metastatic Burden ◽  
First Time ◽  
Do So

Although metastatic disease is the primary cause of mortality in cancer patients, the mechanisms leading to overwhelming metastatic burden are still incompletely understood. Metastases are the endpoint of a series of multi-step events involving cancer cell intravasation, dissemination to distant organs, and outgrowth to metastatic colonies. Here we show, for the first-time, that breast cancer cells do not solely disseminate to distant organs from primary tumors and metastatic nodules in the lymph nodes, but also do so from lung metastases. Thus, our findings indicate that metastatic dissemination could continue even after the removal of the primary tumor. Provided that the re-disseminated cancer cells initiate growth upon arrival to distant sites, cancer cell re-dissemination from metastatic foci could be one of the crucial mechanisms leading to overt metastases and patient demise. Therefore, the development of new therapeutic strategies to block cancer cell re-dissemination would be crucial to improving survival of patients with metastatic disease.

scholarly journals Four new Micarea species from the montane cloud forests of Taita Hills, Kenya

2021 ◽  
Vol 53 (1) ◽  
pp. 81-94
Author(s):  
Annina Kantelinen ◽  
Marko-Tapio Hyvärinen ◽  
Paul M. Kirika ◽  
Leena Myllys
Keyword(s):  
New Species ◽  
Maximum Likelihood ◽  
Maximum Parsimony ◽  
Polarized Light ◽  
Eastern Arc Mountains ◽  
Brown Pigment ◽  
Cloud Forests ◽  
Taita Hills ◽  
First Time ◽  
Existing Data

AbstractThe genus Micarea was studied for the first time in the Taita Hills, Kenya. Based on new collections and existing data, we reconstructed a phylogeny using ITS, mtSSU and Mcm7 regions, and generated a total of 27 new sequences. Data were analyzed using maximum likelihood and maximum parsimony methods. Based mainly on new collections, we discovered four undescribed well-supported lineages, characterized by molecular and phenotypic features. These lineages are described here as Micarea pumila, M. stellaris, M. taitensis and M. versicolor. Micarea pumila is characterized by a minutely granular thallus, small cream-white or pale brownish apothecia, small ascospores and the production of prasinic acid. Micarea stellaris has a warted-areolate thallus, cream-white apothecia usually darker at the centre, a hymenium of light grey or brownish pigment that dissolves in K, and intense crystalline granules that appear as a belt-like continuum across the lower hymenium when studied in polarized light. Micarea taitensis is characterized by a warted-areolate thallus and cream-white or yellowish apothecia that sometimes produce the Sedifolia-grey pigment. Micarea versicolor is characterized by a warted-areolate, sometimes partly granular thallus and apothecia varying from cream-white to light grey to blackish in colour. This considerable variation in the coloration of its apothecia is caused by an occasional mixture of the Sedifolia-grey pigment in the epihymenium and another purplish brown pigment in the hymenium. Micarea stellaris, M. taitensis and M. versicolor produce methoxymicareic acid. The main distinguishing characters are presented in a species synopsis. Three of the new species are nested in the M. prasina group, and the fourth one (M. taitensis) resolves as a basal taxon to the M. prasina group. The new species inhabit montane cloud forests, which have fragmented dramatically throughout the Eastern Arc Mountains in recent decades.

Some Palaeoliths from South Arabia

1954 ◽  
Vol 19 (2) ◽  
pp. 189-218 ◽  
Author(s):  
G. Caton-Thompson
Keyword(s):  
Geographical Society ◽  
South Arabia ◽  
First Time ◽  
Do So

The material here described was found in the Hadhramaut by Elinor Gardner and myself between November 1937 and March 1938. My personal investigation of the Palaeolithic Age was limited by pre-Islamic excavations, and I am therefore indebted to her for the gathering of most of the specimens in situ in terrace gravels, and to her detailed study of their positions.The collection consists mainly of groups from four fairly widely separated localities; the physiography of these has already been outlined in a comprehensive paper published in the Geographical Journal. Whenever appropriate to the purpose of this account, which is to place for the first time on illustrated record all we observed about the palaeoliths, I have reused in this different context illustrations of Quaternary environment which appeared in that Journal. With thanks I acknowledge the permission of the Royal Geographical Society to do so.

Mesoscopic characterization of the optical property of antiphase boundaries in CuPt-ordered GaInP2

1999 ◽  
Vol 588 ◽  
Author(s):  
Y. Ohno ◽  
S. Takeda
Keyword(s):  
Optical Property ◽  
Light Emission ◽  
Polarized Light ◽  
Structural Data ◽  
Luminescence Spectra ◽  
Antiphase Boundaries ◽  
Transmission Electron ◽  
Tem Method ◽  
Low Dimensional ◽  
First Time

AbstractWe have developed an apparatus for polarized cathodoluminescence (CL) spectroscopy combined with transmission electron microscopy (TEM), that enables us to obtain simultaneously structural data in higher spatial resolution by TEM and polarized luminescence spectra by CL of the same microscopic area. The polarized-CL/TEM method is very useful to study the optical properties of low-dimensional microstructures in semiconducting materials. We have applied the method to examine the optical property of antiphase boundaries in CuPt-ordered GaInP2 and found, for the first time, the polarized light emission from the APBs whose habit planes are parallel to the (T11) and (1T0) atomic planes.

Trophallaxis in honeybees, Apis mellifera (L.), as related to their past experience at the food source

2003 ◽  
Vol 66 (4) ◽  
pp. 791-795 ◽  
Author(s):  
Alejandro J Wainselboim ◽  
Walter M Farina
Keyword(s):  
Apis Mellifera ◽  
Food Source ◽  
Past Experience

The chiral coating on an achiral nanostructure by the secondary effect in focused ion beam induced deposition

2021 ◽  
Author(s):  
Chen Fang ◽  
Qing Chai ◽  
Ye Chen ◽  
Yan Xing ◽  
Zai-fa Zhou
Keyword(s):  
Circular Dichroism ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polarized Light ◽  
Localized Surface Plasmon ◽  
Light Illumination ◽  
Secondary Effect ◽  
Circularly Polarized Light ◽  
Optical Metamaterials ◽  
Circular Dichroïsm

Abstract Optical metamaterials are widely used in electromagnetic wave modulation due to their sub-wavelength feature sizes. In this paper, a method to plate an achiral nanopillar array with chiral coating by the secondary effect in focused ion beam induced deposition is proposed. Guided by the pattern defined in a bitmap with variable residence time, the beam scan strategy suppresses the interaction between adjacent nanostructures. A uniform chiral coating is formed on the target nanostructure without affecting the adjacent nanostructure, under carefully selected beam parameters and the rotation angle of the sample stage. Energy Dispersive X-Ray Spectroscopy results show that the chiral film has high purity metal, which enables the generation of localized surface plasmon resonances and causes the circular dichroism under circularly polarized light illumination. Finally, the tailorable circular dichroism spectrum of the coated array is verified by the Finite Difference Time Domain method.

scholarly journals METODE INTERAKSI PARENTING: UPAYA MENGOPTIMALKAN PENDIDIKAN SISWA SEJAK DINI

2016 ◽  
Vol 3 (02) ◽  
Author(s):  
Moh Rifai
Keyword(s):  
Life Cycle ◽  
Elementary Students ◽  
Key Words ◽  
Well Being ◽  
Good Schools ◽  
Children Education ◽  
First Time ◽  
Do So ◽  
The Way

<p>Parents are obliged to take care of their children’s future, especially by rendering sufficient education. Children are believed to bring about happiness every now and then, who generate family’s pride up to the almighty judication. Some people are save and some are not in that court, where children will give sigificant contribution in it. That’s why the children’s well being has become the parents obligation. To bring about children’s well being, parents should also render the good treatments during the life cycle of their children. The main duties of parents for their children are giving them the good names, sending them to the good schools where they can learn religion, and marry them to their good spouses. Psychologically, when children are sent to school for the first time, they will feel that they are put apart from parents’ care, so that may of them have to go difficult phase of adjustment. The adjustment includes that of education so as to run as naturally as possible. To get the naturality of the education delegation, teachers and educators are obliged to be able to nurture any value to students as naturally as possible. Parenting model of teaching serves the requirements of teaching children just the way the parrents do, so that it is assumptively effective in teaching elementary students by taking consideration on the psychologial aspect of children.</p><p> </p><p>Key words:   Parenting Model of teaching, children education optimalization</p>

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