2,894 research outputs found
Building Cross Cultural Competencies
The Building Cross Cultural Competencies project was developed with the aim of equipping undergraduate students at the University of York with skills to work in the globalised world, while at the same time assisting with the induction and orientation of international students, new to the institution and to study in the UK. The inspiration for the programme dates back to 2006, when one of the authors visited three Universities in New Zealand and Australia. These Universities were perceived to be further down the route to internationalisation (as defined by Knight 2003) than was the norm in the UK at the time. Innovations observed at Massey and Waikato Universities in New Zealand and the University of Sydney, Australia, were redesigned and redeveloped for use at the University of York, with the agreement of the staff involved at those institutions. In particular, a cross cultural communication module and two distinctive peer mentor schemes provided the nucleus of the idea for a new initiative at York that would span the employability and internationalisation agendas This paper identifies how the project redesigned and developed ideas taken from Australian and New Zealand Universities for use in a UK context. It makes links to the literature on student adjustment and institutional adaptation; peer teaching and cross cultural communication skills. It will also consider the problems and difficulties experienced as the project progressed.
Gulf Stream trajectories measured with free-drifting buoys
Also published as: Journal of Physical Oceanography 11 (1981): 999-1010During 1975-78, 35 free-drifting buoys measured surface currents in the Gulf Stream region. The buoy
trajectories trace numerous paths of the Stream and show that the Stream is strongly influenced by the
New England Seamounts. This influence is manifested as 1) a quasi-permanent, 100 km, southeastward
deflection of the Stream and the frequent occurrence of a ring meander over the seamounts; 2) large-amplitude
meanders beginning at the seamounts and extending eastward; and 3) small, 20 km diameter
eddies which appear to be generated locally by individual seamounts.
A chart of the mean temperature field at a depth of 450 m agrees with several of the patterns seen in the
buoy trajectories. West of the seamounts, the mean path of the Gulf Stream is eastward; over the seamounts,
the path turns sharply northeastward and the isotherms in the Stream abruptly diverge.Prepared for the Office of Naval Research under Contract
N000 14-74-C- 0262; NR 083-004 and for the National Science
Foundation under Grant OCE 78-18017
Upwind dynamic soaring of albatrosses and UAVs
Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Progress in Oceanography 130 (2015): 146-156, doi:10.1016/j.pocean.2014.11.002.Albatrosses have been observed to soar in an upwind direction using what is called here an upwind mode of dynamic soaring. The upwind mode is modeled using the dynamics of a two-layer Rayleigh cycle in which the lower layer has zero velocity and the upper layer has a uniform wind speed of W. The upwind mode consists of a climb across the wind-shear layer headed upwind, a 90° turn and descent across the wind- shear layer perpendicular to the wind, followed by a 90° turn into the wind. The increase of airspeed gained from crossing the wind-shear layer headed upwind is balanced by the decrease of airspeed caused by drag. Results show that a wandering albatross can soar over the ocean in an upwind direction at a mean speed of 8.4 m/s in a 3.6 m/s wind, which is the minimum wind speed necessary for sustained dynamic soaring. The main result is that an albatross can soar upwind much faster that the wind speed. The upwind dynamic soaring mode of a possible robotic albatross UAV (Unmanned Aerial Vehicle) is also modeled using a Rayleigh cycle. Maximum possible airspeeds are approximately equal to 9.5 times the wind speed of the upper layer. In a wind of 10 m/s, the maximum possible upwind (56 m/s) and across-wind (61 m/s) components of UAV velocity over the ocean result in a diagonal upwind velocity of 83 m/s. In sufficient wind, a UAV could, in principle, use fast diagonal speeds to rapidly survey large areas of the ocean surface and the marine boundary layer. Limitations to achieving such fast travel velocity are discussed and suggestions are made for further studies.Financial support was provided by the F. Livermore Trust and Woods Hole Oceanographic Institution emeritus funds
Da Vinci’s observations of soaring birds
Author Posting. © American Institute of Physics, 2017. This article is posted here by permission of American Institute of Physics for personal use, not for redistribution. The definitive version was published in Physics Today 70, no. 11 (2017): 78, doi:10.1063/PT.3.3773.With only a minimal flapping, the wandering albatross can circumnavigate the globe. During its peregrinations over the Southern Ocean, the seabird exploits wind shear—the gradient of wind speed—to extract energy for its sustained flight. That same maneuver, called dynamic soaring, is used by pilots of radio-controlled gliders. In flights that take advantage of the shear associated with wind blowing over mountain ridges, the gliders reach air speeds of an astonishing 500 mph. Engineers are currently developing autonomous unmanned vehicles that can use the technique to supplement different sources of energy for sustained flight over the oceans. Possible applications include environmental monitoring, surveillance, and search and rescue.2018-11-0
Agulhas leakage into the Atlantic estimated with subsurface floats and surface drifters
Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 54 (2007): 1361-1389, doi:10.1016/j.dsr.2007.04.010.Surface drifters and subsurface floats drifting at depths near 800 m were used to study the
pathways of warm salty Indian Ocean water leaking into the South Atlantic that is a
component of the upper limb of the Atlantic meridional overturning circulation. Four
drifters and 5 floats drifted from the Agulhas Current directly into the Benguela Current.
Others looped for various amounts of time in Agulhas rings and cyclones, which
translated westward into the Atlantic contributing a large part of Indian Ocean leakage.
Agulhas rings translated into the Benguela Current where they slowly decayed. Some
large blob-like Agulhas rings with irregular shapes were found in the southeastern Cape
Basin. Drifter trajectories suggest these rings become more circular with time eventually
evolving into the circular rings observed west of the Walvis Ridge. Agulhas cyclones,
which form on the north side of the Agulhas south of Africa, translated southwestward
(to 6°E) and contributed water to the southern Cape Basin. A new discovery is a
westward extension from the mean Agulhas retroflection measured by westward drifting
floats near 41ºS out to at least 5ºW with some floats as far west as 25ºW. The Agulhas
extension appears to split the South Atlantic Current into two branches and to transport
Agulhas water westward where it is mixed and blended with eastward-flowing water
from the western Atlantic. The blended mixture flows northeastward in the northern
branch of the South Atlantic Current and into the Benguela Current. Agulhas leakage
transport was estimated from drifters and floats to be at least 15 Sv in the upper 1,000 m,
which is equivalent to the transport of the upper layer meridional overturning circulation.
It is suggested that the major component of the upper layer overturning circulation in the
Atlantic is Agulhas leakage.Funds for this
research were provided by National Science Foundation grants OCE-0236654 to the Woods Hole
Oceanographic Institution and OCE-0236527 to the Woods Hole Research Center
High-speed dynamic soaring
Author Posting. © B2Streamlines.com, 2012. This article is posted here by permission of B2Streamlines.com for personal use, not for redistribution. The definitive version was published in R/C Soaring Digest 29, no. 4 (2012): 36-49.Dynamic soaring uses the gradient of wind velocity (wind shear)
to gain energy for energy-neutral flight. Recently, pilots of radiocontrolled
gliders have exploited the wind shear associated
with fast winds blowing over mountain ridges to achieve very
fast speeds, reaching a record of 487 mph in January 2012.
A relatively simple two-layer model of dynamic soaring was
developed to investigate factors that enable such fast speeds.
The optimum period and diameter of a glider circling across a
thin wind-shear layer predict maximum glider airspeed to be
around 10 times the wind speed of the upper layer (assuming a
maximum lift/drag of around 30). The optimum circling period
can be small ~1.2 seconds in fast dynamic soaring at 500
mph, which is difficult to fly in practice and results in very large
load factors ~100 times gravity. Adding ballast increases the
optimum circling period toward flyable circling periods of 2-3
seconds. However, adding ballast increases stall speed and the
difficulty of landing without damage. The compressibility of air
and the decreasing optimum circling period with fast speeds
suggest that record glider speeds will probably not increase
as fast as they have during the last few years and will probably
level out below a speed of 600 mph
The influence of Hellenistic philosophy on Paul\u27s figurative temple language applied to the Corinthians
https://place.asburyseminary.edu/ecommonsatsdissertations/1820/thumbnail.jp
Carbohydrate metabolism in rats with adrenocortical transplants
This item was digitized by the Internet Archive. Thesis (Ph.D.)--Boston UniversityMany studies have been made of the part played the adrenal cortex in carbohydrate metabolism. The conclusions of these studies are chiefly based on the use of animals in the terminal stages of adrenal insufficiency, and are therefore subject to criticism. The use of the adrenalectomized rat with autoplastic adrenocortical tissue is considered to obviate some of these criticisms.
A review of the literature of carbohydrate metabolism and the factors affecting it is given. The regulation of carbohydrate metabolism by the glands of internal secretion is discussed, with emphasis on the part played by the adrenal cortex. Adrenal cortical hormones possessing "cortin activity", and their assay, are reviewed, their comparative effects considered and summarized. A review of the studies made on carbohydrate metabolism in adrenalectomized rats is included.
The problem of relative insufficiency of adrenocortical hormone is discussed and the literature reviewed. Studies of the rat with transplanted cortical tissue have shown that the transplanted tissue is able to maintain the life and health of the animal under ordinary conditions, but is not able to function as efficiently as does the normal gland under conditions of stress. The blood sugar in the rat with transplanted cortical tissue has been investigated but the literature contains no studies of the glycogen levels in such animals.
EXPERIMENTAL PART. A mixed stock of male albino rats were bilaterally adrenalectomized (by the lumbar approach), followed by implantation of the removed glands (all in one operation) and a sufficient period of recovery (not less than six weeks). From these, one group of rats was subjected to a fasting period of 24 hours. Free access to water was allowed during the period. At the end of the fasting, period, the rats were anesthetized with sodium amytal (intraperitoneal injection - 10 mgms. per 100 gms. body weight). The abdominal cavity was opened and a sample of blood was obtained from the vena cava. The whole liver then was removed, weighed, and immediately placed in hot 30% potassium hydroxide solution. Samples of gastrocnemius muscle were obtained, weighed, and promptly placed in hot 30% potassium hydroxide. Determinations were made of the blood glucose (using the Somogyi-Shaffer-Hartman iodometric titration method), and of the glycogen of the liver and muscles (using Good, Kramer, and Somogyi's modification of Pflüger's method). A control group of intact animals was subjected to the same procedure.
On other groups (including one group of completely adrenalectomized rats) a glucose meal was given at the end of the 24 hour fasting period. The procedure was as follows: At the end of the 24 hour fasting period, the rats were fed glucose solution (1.065 gms. glucose per 100 gms. body weight) by stomach tube without anesthesia or excitement. After an interval of one hour, one animal from each group wae anesthetized. Samples of blood and gastrocnemius muscle, and the whole livers were removed for glucose or glycogen analyses. The same procedure was carried out at the end of two, three, and so on, hours, up to seven hours, after the glucose meal. Determinations were made of the blood glucose, and the glycogen of the liver and muscles.
RESULTS. At the end of the 24 hour fasting period, in seven normal male rats the blood glucose averaged 77 mgms. per 100 cc. whole blood (range, 66 - 93 mgms.); liver glycogen, 32 mgms. per 100 gms. wet liver (range, 8-83 mgms.); and muscle glycogen, 323 mgms. per 100 gms. wet muscle (range, 240 - 433 mgms.).
Eleven male rats with adrenocortical transplants shoved the following picture after 24 hours of fasting: blood glucose averaged 80 mgms. per 100 cc. whole blood (range, 62-94 mgms.); liver glycogen 35 mgms. per 100 gms. wet liver (range, 4-91 mgms.); and muscle glycogen, 484 mgms. per 100 gms. wet muscle (range, 400 - 591 mgms.).
These values are considered to be within the normal range, and in agreement with average values obtained by other investigators. It is concluded that the adrenalectomized rat with transplanted adrenal cortical tissue is like the normal rat after a 24 hour fasting period with respect to blood glucose, liver glycogen, and muscle glycogen.
in the groups of animals given a glucose meal, the following results were obtained. The glucose tolerance curve of the rat with adrenocortical transplants was like that of the normal with respect to shape, but the curve was less sharp, and had slightly lower values than that of the normal intact animal. With respect to liver glycogen, the adrenalectomized animal failed to deposit any during a five hour period; the adrenalectomized rat with adrenocortical transplants did not store glycogen in the liver at a rate comparable to the intact animal, and in a seven hour period did not reach the levels attained by the normal animal. The adrenalectomized rat stored glycogen in the muscles, but not at the same rate as the normal or the 'transplant'. The normal rat and the rat with 'transplants' kept pace with each other in their ability to store glycogen in the muscles for the first four hours after the glucose meal, but at that point the storage mechanisms of the rat with 'transplants' appeared to have settled down to a steady rate, lower than that of the normal, while the rate at which the normal rat stored glycogen continued to increase.
On the basis of these results, the glucose tolerance curve in the rat with 'transplants' is considered to be normal, and it is concluded that no gross differences in the rate of absorption exist in the 'transplant'.
Explanations are considered for the leveling off of the curve of glycogen storage in the muscle of the 'transplant'. On the basis of previous evidence obtained on the adrenalectomized rat, it is suspected that increased utilization explains this difference between the 'transplant' and the normal, and that the animal with 'transplants' is deficient in the amount (or kind) of hormone produced by the regenerated cortical tissue which controls glycogen storage in the muscle.
The impaired ability of the rat with 'transplants' to store glycogen in the liver at the same rate or to the sane extent as the normal is discussed. It is possible that in the 'transplant' there is a failure of the transplanted tissue to produce, to the same degree as the normal, the hormone which controls gluconeogenesis in the liver.
It is suggested that an impairment of the carbohydrate metabolism may be related to the increased susceptibility of the 'transplant' to histamine and anaphylactic shock. It is also suggested that the hormones of the cortex may act synergistically with adrenaline on the organism in times of stress particularly.
The intermediacy of the 'transplant' to the normal and the adrenalectomized rat with respect to carbohydrate metabolism is considered, and it ie observed that the evidence supports the theory that the adrenalectomized rat with transplanted cortical tissue does not function as efficiently as does the normal animal in acute emergencies.
It is concluded that (a) the carbohydrate levels in the adrenalectomized rat with adrenocortical transplants are like those of the normal rat after a 24 hour period of fasting; (b) the rat with 'transplants' differs from the normal animal in those mechanisms responsible for the storage of glycogen in the tissues, being intermediate in this respect to the normal and the completely adrenalectornized rat, but more like the former; (c) possible explanations for this difference between the storage levels of the 'transplant' and the normal rat are that a relative cortical and/or medullary deficiency in the former leads to a decreased gluconeogenesis in the liver, and eventually increased utilization of carbohydrate in the muscle
High-speed robotic albatross : unmanned aerial vehicle powered by dynamic soaring
Author Posting. © B2Streamlines.com, 2012. This article is posted here by permission of B2Streamlines.com for personal use, not for redistribution. The definitive version was published in R/C Soaring Digest 29, no. 6 (2012): 4-18.Wandering albatrosses exploit the
vertical gradient of wind velocity (wind
shear) above the ocean to gain energy
for long distance dynamic soaring
with a typical airspeed of 36 mph. In
principle, albatrosses could soar much
faster than this in sufficient wind, but the
limited strength of their wings prevents
a much faster airspeed. Recently, pilots
of radio-controlled (RC) gliders have
exploited the wind shear associated with
winds blowing over mountain ridges to
achieve very fast glider speeds, reaching
a record of 498 mph in March 2012.
A relatively simple two-layer model of
dynamic soaring predicts maximum
glider airspeed to be around 10 times the
wind speed of the upper layer (assuming
zero wind speed in the lower layer). This
indicates that a glider could soar with an
airspeed of around 200 mph in a wind
speed of 20 mph, much faster than an
albatross. It is proposed that recent highperformance
RC gliders and their pilots’
expertise could be used to develop
a high-speed robotic albatross UAV
(Unmanned Aerial Vehicle), which could
soar over the ocean like an albatross,
but much faster than the bird. This UAV
could be used for various purposes such
as surveillance, search and rescue, and
environmental monitoring. A first step is
for pilots of RC gliders to demonstrate
high-speed dynamic soaring over the
ocean in realistic winds and waves
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