17,091 research outputs found
DNA extraction from formalin-fixed Franciscana tissues
The present paper reports the extraction of DNA from formalin-fixed Pontoporia blainvillei tissues. Following the Vachot and Monerot (1996) protocol, fragmented DNA (300-700bp) was extracted from more than 95% of liver and muscle samples. DNA yield in liver samples was significantly higher than in muscle samples (4.574 ± 1.169mg DNA/mg versus 0.808 ± 0.297mg DNA/mg). Similar results were obtained from nine other species of cetaceans and five species of pinnipeds. It is of special interest to have a method that allows the utilisation of museum specimens not originally preserved for genetic studies,
which may include rarely available, declining or extinct species.
SPANISH: El presente trabajo reporta la extracción de ADN a partir de tejidos formolizados de Pontoporia blainvillei. Siguiendo el protocolo de Vachot y Monerot (1996) se pudo extraer ADN degradado (300-700pb) en más del 95% de las muestras de hígado y músculo analizadas. El rendimiento en ADN fue significativamente mayor en muestras de hígado que en muestras de músculo (4.574 ± 1.169mg DNA/mg tejido húmedo versus 0.808 ± 0.297mg DNA/mg tejido húmedo). Resultados similares se obtuvieron en otras nueve especies de Cetáceos y cinco de Pinnípedos. Resulta de gran interés contar con un método que permita la utilización de especímenes depositados en museos y que no hayan sido originalmente colectados para estudios genéticos, incluyendo especies de difícil obtención, en franca declinación o extintas
Star-formation in the central kpc of the starburst/LINER galaxy NGC1614
A high angular resolution, multi-wavelength study of the LINER galaxy NGC1614
has been carried out. OVRO CO 1-0 observations are presented together with
extensive multi-frequency radio continuum and HI absorption observations with
the VLA and MERLIN. Toward the center of NGC1614, we have detected a ring of
radio continuum emission with a radius of 300 pc. This ring is coincident with
previous radio and Paschen-alpha observations. The dynamical mass of the ring
based on HI absorption is 3.1 x 10E9 Msun. The peak of the integrated CO 1-0
emission is shifted by 1" to the north-west of the ring center and a
significant fraction of the CO emission is associated with a crossing dust
lane. An upper limit to the molecular gas mass in the ring region is 1.7 x 10E9
Msun. Inside the ring, there is a north to south elongated 1.4GHz radio
continuum feature with a nuclear peak. This peak is also seen in the 5GHz radio
continuum and in the CO. We suggest that the R=300 pc star forming ring
represents the radius of a dynamical resonance - as an alternative to the
scenario that the starburst is propagating outwards from the center into a
molecular ring. The ring-like appearance probably part of a spiral structure.
Substantial amounts of molecular gas have passed the radius of the ring and
reached the nuclear region. The nuclear peak seen in 5GHz radio continuum and
CO is likely related to previous star formation, where all molecular gas was
not consumed. The LINER-like optical spectrum observed in NGC1614 may be due to
nuclear starburst activity, and not to an Active Galactic Nucleus (AGN).
Although the presence of an AGN cannot be excluded.Comment: Accepted by Astronomy and Astrophysics, 12 pages, 10 figure
B747/JT9D flight loads and their effect on engine running clearances and performance deterioration; BCAC NAIL/P and WA JT9D engine diagnostics programs
Flight loads on the 747 propulsion system and resulting JT9D blade to outer airseal running clearances during representative acceptance flight and revenue flight sequences were measured. The resulting rub induced clearance changes, and engine performance changes were then analyzed to validate and refine the JT9D-7A short term performance deterioration model
Duality in Shearing Rheology Near the Athermal Jamming Transition
We consider the rheology of soft-core frictionless disks in two dimensions in
the neighborhood of the athermal jamming transition. From numerical simulations
of bidisperse, overdamped, particles, we argue that the divergence of the
viscosity below jamming is characteristic of the hard-core limit, independent
of the particular soft-core interaction. We develop a mapping from soft-core to
hard-core particles that recovers all the critical behavior found in earlier
scaling analyses. Using this mapping we derive a duality relation that gives
the exponent of the non-linear Herschel-Bulkley rheology above jamming in terms
of the exponent of the diverging viscosity below jamming.Comment: 5 pages, 4 figures. Manuscript revisions: new title, additional text
concerning connections to experiment, revised Fig. 4, other minor changes and
clarifications in text. Conclusions remain essentially unchanged. Accepted
for publication in Phys. Rev. Let
Timelessly Present, Compassionately Impassible: A Defense of Two Classical Divine Attributes
This study articulates a God-concept in the tradition of classical Christian theism, contending with calls to modify significantly or revise classical constructions. Attention falls upon two closely related divine attributes that have, especially in recent decades, come under philosophical and theological attack – God’s timelessness and impassibility (inability to suffer). Is the “classical” Lord truly Immanuel, i.e. with us? This general question motivates the study.
The opening three chapters analyze aspects of the God-concepts put forth by Augustine, Aquinas, and Calvin. Apparent tensions between a timeless transcendence and an affirming union of the Trinity with creation are countenanced, with an eye to doing justice to both doctrines. Chapter One examines the idea of divine timelessness and corresponding thoughts about temporal reality found in the Confessions, supplementing Augustinian transcendence with the creational and eschatological insights of two other Church Fathers. Chapter Two documents Aquinas’s affirmation of both God’s strong immutability and the non-necessity of creation, while questioning whether he affirms these in a logically consistent way. Chapter Three then follows the contours of Calvin’s Trinitarianism and Christology, reflecting on the Triune Creator’s gracious “wedding” of himself to the whole work of creation.
The final three chapters operate within the fields of philosophy and philosophical theology. Chapter Four commends a tenseless (or B) theory of time, highlighting several problems surrounding tensed (or A) theories of time. But this former view implies that there is no “official present,” leaving no apparent room for the presence of the timeless God with times and temporally located agents. Thus Chapter Five seeks to address classical eternalism’s “present problem.” The conclusion is reached that the temporally absent God’s “present problem” can be resolved by embracing a “risk-free” understanding of divine providence, best understood in terms of a “Reformed decree” that strongly actualizes all non-divine entities and events. Chapter Six begins by wrestling with what implications the timelessness doctrine might have for “responsive” divine compassion and ends by proposing that the infinite God “embraces” the finite world not by way of a panentheistic inclusion but in some ways more akin to a husband’s attentive care for his wife
Two phase transitions in the fully frustrated model
The fully frustrated model on a square lattice is studied by means of
Monte Carlo simulations. A Kosterlitz-Thouless transition is found at , followed by an ordinary Ising transition at a slightly
higher temperature, . The non-Ising exponents reported by
others, are explained as a failure of finite size scaling due to the screening
length associated with the nearby Kosterlitz-Thouless transition.Comment: REVTEX file, 8 pages, 5 figures in uuencoded postscrip
Unitary ambiguity in the extraction of the E2/M1 ratio for the transition
The resonant electric quadrupole amplitude in the transition is of great interest for the understanding of
baryon structure. Various dynamical models have been developed to extract it
from the corresponding photoproduction multipole of pions on nucleons. It is
shown that once such a model is specified, a whole class of unitarily
equivalent models can be constructed, all of them providing exactly the same
fit to the experimental data. However, they may predict quite different
resonant amplitudes. Therefore, the extraction of the E2/M1() ratio (bare or dressed) which is based on a dynamical
model using a largely phenomenological interaction is not unique.Comment: 10 pages revtex including 4 postscript figure
Universal Behavior in Excited Heavy-Light and Light-Light Mesons
A common pattern of large orbital and radial excitations in heavy-light and
light-light mesons is demonstrated. Within a general potential model the Regge
slopes of the light degrees of freedom for these mesons are shown to be in the
ratio of two. The possibility of ``tower'' degeneracy occurs only with pure
scalar confinement.Comment: Latex, 10 pages, 2 figures placed using epsf.sty. Z-compressed
postscript version available at
http://phenom.physics.wisc.edu/pub/preprints/1996/madph-96-970.ps.Z or at
ftp://phenom.physics.wisc.edu/pub/preprints/1996/madph-96-970.ps.
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The Physio-Chemical Properties for the Interior of Enceladus
We have reviewed the current physical and chemical conditions of the Enceladus sub-surface environment, including the composition, temperature, pH and pressure. Here we have defined some of these parameters and, through the aid of modelling, will define and refine the remaining parameters needed for our experimental work. Simulations of the chemical reactions occurring within Enceladus can then be carried
out to advance our understanding of the internal environment of Enceladus and help evaluate its potential habitability. Once a better understanding of the chemical reactions occurring at the rock-water interface has been carried out, then potential analogues on Earth can be evaluated and known microbial life can be tested to see if it could survive the conditions of Enceladus
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