scholarly journals A comparison of the Emlen funnel and Busse's flat cage for orientation studies

Ring ◽  
2004 ◽  
Vol 26 (1) ◽  
pp. 59-69
Author(s):  
Agnieszka Ożarowska ◽  
Reuven Yosef
Keyword(s):  
Angular Dispersion ◽  
Orientation Data ◽  
Normal Feature ◽  
Williams Test

A comparison of the Emlen funnel and Busse's flat cage for orientation studies The Emlen funnel cage was introduced in 1966. Since then it has been used in numerous studies on bird orientation. In 1995, Busse proposed another technique - in the form of flat, round cylindrical cage. Busse also tested nocturnal migrants in the daytime. He, and Nowakowski and Malecka (1999), proved that birds tested in daylight and at night displayed similar distributions of their preferred directions. This study also supports their findings. Zehtindijev et al. (2003) found that results in the Emlen funnel and Busse's flat cage were coherent, despite the tests were performed in different conditions (night-day) and in different years. This study is the first one that compares results of the same individuals tested in the two types of orientation cages during the day (N = 75) and night (N = 17). Results of both methods did not differ (Watson-Williams test of mean angles, Mann-Whitney U-test of angular dispersion) both during the day and at night. Multiheading bird behaviour is common in both types of cages and seems to be a normal feature of orientation data. The only difference was found in bird activity (i.e. number of scratches during 10 minutes of testing) that was higher for Busse's flat cage in daytime tests.

Localization of Intracisternal a Particle Antigens in Neoplastic Cells and Preimplantation Mouse Embryos

1980 ◽  
Vol 38 ◽  
pp. 696-697
Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco
Keyword(s):  
Endoplasmic Reticulum ◽  
Normal Development ◽  
Mouse Embryos ◽  
Neoplastic Cells ◽  
Large Numbers ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Intracisternal A Particle ◽  
Normal Feature

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.

scholarly journals Quantitative estimates of average geomagnetic axial dipole dominance in deep geological time

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrew J. Biggin ◽  
Richard K. Bono ◽  
Domenico G. Meduri ◽  
Courtney J. Sprain ◽  
Christopher J. Davies ◽  
...  
Keyword(s):  
Power Law ◽  
Geomagnetic Field ◽  
Recent Observation ◽  
Observational Constraint ◽  
Angular Dispersion ◽  
Geological Time ◽  
Future Studies ◽  
Axial Dipole ◽  
Quantitative Estimates

AbstractA defining characteristic of the recent geomagnetic field is its dominant axial dipole which provides its navigational utility and dictates the shape of the magnetosphere. Going back through time, much less is known about the degree of axial dipole dominance. Here we use a substantial and diverse set of 3D numerical dynamo simulations and recent observation-based field models to derive a power law relationship between the angular dispersion of virtual geomagnetic poles at the equator and the median axial dipole dominance measured at Earth’s surface. Applying this relation to published estimates of equatorial angular dispersion implies that geomagnetic axial dipole dominance averaged over 107–109 years has remained moderately high and stable through large parts of geological time. This provides an observational constraint to future studies of the geodynamo and palaeomagnetosphere. It also provides some reassurance as to the reliability of palaeogeographical reconstructions provided by palaeomagnetism.

Rethinking the use of disruptive pop-up encounters for transformation: A missional reading of Acts 8:26–40

2021 ◽  
pp. 009182962110035
Author(s):  
Thinandavha Derrick Mashau
Keyword(s):  
Holy Spirit ◽  
Search For Meaning ◽  
Christian Mission ◽  
Global Context ◽  
The Holy Spirit ◽  
Normal Feature

Socio-economic, political and religious pop-ups are a normal feature in the global context. While some are disruptive and annoying, others can be very useful. This article, through a missional reading of Acts 8:26–40, seeks to draw missiological lessons from disruptive pop-up encounter(s) in this text. A missional reading of Acts 8:26–40 discovered that the Holy Spirit is not only the author of Christian mission, but also the pop-up Spirit of God, who prompted pop-up encounters between two strangers whose pop-up experience became an encounter that transformed their search for meaning, understanding, transformative ecclesiologies and the praxes thereof. Therefore, disruptive pop-up encounters, creatively embraced and used, are able to generate encountering conversations that are liberating and transforming.

scholarly journals Rheological Contrast between Quartz and Coesite Generates Strain Localization in Deeply Subducted Continental Crust

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 842
Author(s):  
Kouhei Asano ◽  
Katsuyoshi Michibayashi ◽  
Tomohiro Takebayashi
Keyword(s):  
Rheological Behavior ◽  
Strain Localization ◽  
Shear Zones ◽  
Ultrahigh Pressure ◽  
Ultramafic Rocks ◽  
Crustal Material ◽  
Orientation Data ◽  
Crystallographic Preferred Orientation ◽  
Dabie Shan ◽  
Felsic Rocks

Deformation microstructures of peak metamorphic conditions in ultrahigh-pressure (UHP) metamorphic rocks constrain the rheological behavior of deeply subducted crustal material within a subduction channel. However, studies of such rocks are limited by the overprinting effects of retrograde metamorphism during exhumation. Here, we present the deformation microstructures and crystallographic-preferred orientation data of minerals in UHP rocks from the Dabie–Shan to study the rheological behavior of deeply subducted continental material under UHP conditions. The studied samples preserve deformation microstructures that formed under UHP conditions and can be distinguished into two types: high-strain mafic–ultramafic samples (eclogite and garnet-clinopyroxenite) and low-strain felsic samples (jadeite quartzite). This distinction suggests that felsic rocks are less strained than mafic–ultramafic rocks under UHP conditions. We argue that the phase transition from quartz to coesite in the felsic rocks may explain the microstructural differences between the studied mafic–ultramafic and felsic rock samples. The presence of coesite, which has a higher strength than quartz, may result in an increase in the bulk strength of felsic rocks, leading to strain localization in nearby mafic–ultramafic rocks. The formation of shear zones associated with strain localization under HP/UHP conditions can induce the detachment of subducted crustal material from subducting lithosphere, which is a prerequisite for the exhumation of UHP rocks. These findings suggest that coesite has an important influence on the rheological behavior of crustal material that is subducted to coesite-stable depths.

A Simple Algorithm to Eliminate Ambiguities in EBSD Orientation Map Visualization and Analyses: Application to Fatigue Crack-Tips/Wakes in Aluminum Alloys

2010 ◽  
Vol 16 (6) ◽  
pp. 831-841 ◽  
Author(s):  
Vipul K. Gupta ◽  
Sean R. Agnew
Keyword(s):  
Fatigue Crack ◽  
Aluminum Alloys ◽  
Direct Determination ◽  
Simple Algorithm ◽  
Electron Backscattered Diffraction ◽  
Lattice Curvature ◽  
Orientation Data ◽  
Orientation Map ◽  
Crack Tips ◽  
Map Visualization

AbstractA simple algorithm is developed and implemented to eliminate ambiguities, in both statistical analyses of orientation data (e.g., orientation averaging) and electron backscattered diffraction (EBSD) orientation map visualization, caused by symmetrically equivalent orientations and the wrap-around or umklapp effect. Using crystal symmetry operators and the lowest Euclidian-distance criterion, the orientation of each pixel within a grain is redefined. An advantage of this approach is demonstrated for direct determination of the representative orientation of a grain within an EBSD map by mean, median, or quaternion-based averaging methods that can be further used within analyses or visualization of misorientation or geometrically necessary dislocation (GND) density. If one also considers the lattice curvature tensor, five components of the dislocation density tensor—corresponding to a part of the GND content—may be inferred. The methodology developed is illustrated using EBSD orientation data obtained from the fatigue crack-tips/wakes in aerospace aluminum alloys 2024-T351 and 7050-T7451.

scholarly journals Angular dispersion compensation for acousto-optic devices used for ultrashort-pulsed laser micromachining

2001 ◽  
Vol 9 (4) ◽  
pp. 200 ◽  
Author(s):  
B.K. Ann Ngoi ◽  
Krishnan Venkatakrishnan ◽  
L.E.N. Lim ◽  
B. Tan
Keyword(s):  
Dispersion Compensation ◽  
Pulsed Laser ◽  
Laser Micromachining ◽  
Angular Dispersion ◽  
Ultrashort Pulsed Laser

scholarly journals Beam tilt and angular dispersion in broad-bandwidth, nanosecond optical parametric oscillators

1999 ◽  
Vol 16 (9) ◽  
pp. 1525 ◽  
Author(s):  
W. J. Alford ◽  
Russell J. Gehr ◽  
R. L. Schmitt ◽  
A. V. Smith ◽  
Gunnar Arisholm
Keyword(s):  
Optical Parametric Oscillators ◽  
Angular Dispersion ◽  
Broad Bandwidth ◽  
Parametric Oscillators ◽  
Optical Parametric

DATACON: A quickbasic program to reformat orientation data from faults

1998 ◽  
Vol 24 (6) ◽  
pp. 585-590 ◽  
Author(s):  
Christopher Shorrock ◽  
Richard J. Lisle
Keyword(s):  
Orientation Data

scholarly journals Measurement of motion corrected wind velocity using an aerostat lofted sonic anemometer

2013 ◽  
Vol 6 (1) ◽  
pp. 703-720 ◽  
Author(s):  
W. R. Stevens ◽  
W. Squier ◽  
W. Mitchell ◽  
B. K. Gullett ◽  
C. Pressley
Keyword(s):  
Reference System ◽  
Meteorological Data ◽  
Translational Motion ◽  
Sonic Anemometer ◽  
Wind Data ◽  
Measurement Unit ◽  
Dispersion Modeling ◽  
Plume Dispersion ◽  
Fire Plume ◽  
Orientation Data

Abstract. An aerostat-lofted, sonic anemometer was used to determine instantaneous 3 dimensional wind velocities at altitudes relevant to fire plume dispersion modeling. An integrated GPS, inertial measurement unit, and attitude heading and reference system corrected the wind data for the rotational and translational motion of the anemometer and rotated wind vectors to a global North, West, Up coordinate system. Data were taken at rates of 10 and 20 Hz to adequately correct for motion of the aerostat. The method was applied during a prescribed forest burn. These data were averaged over 15 min intervals and used as inputs for subsequent dispersion modeling. The anemometer's orientation data are demonstrated to be robust for converting the wind vector from the internal anemometer reference system to the global reference system with an average bias between 5 and 7°. Lofted wind data are compared with sonic anemometer data acquired at 10 m on a mast located near the tether point of the aerostat and with local meteorological data.

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