5,273 research outputs found
Valor nutricional de los hidratos de carbono de los alimentos: integraciĂłn de los estudios quĂmicos y biolĂłgicos
Fondecyt Regular 1980893 año 199
An Analysis of Early Modern Philosopher Mary Astell and a Critique of the Western Canon
In my paper I address the unfoundedness of leaving out certain voices in the historical studies of philosophy. In order to make this point I investigate a brilliant thinker of the 17th and 18th centuries, Mary Astell. I also address, analyze and critique the Western Canon for leaving out the philosophies of women, and highlight social constructivism and social representation theory in education and the philosophies behind these concepts. Despite the misleading drift of the Western canon, there were brilliant female thinkers throughout the history of philosophy. Telling only a single story of something that has so much depth, history, and culture can come with unintended consequences, for example, the exclusion of marginalized people from the discipline of philosophy as well as the perpetuation of âother-ing.â Mary Astell is one of the many voices who deserves to be studied and discussed just as much as any other male philosopher, if for no other reason than her early foreshadowing of social constructivism in her educational theory. Her radical ideas exemplify how she was capable of reason and advocated for the other women whom she knew were also capable. This is an example of the way philosophy can avoid telling a single story and recover forgotten voices of history without disregarding the legacies like Cartesianism
Determination of Frequency and Distribution of Hessian Fly (Diptera: Cecidomyiidae) Biotypes in the Northeastern Soft Wheat Region
Fifteen collections of Hessian flies from the northern soft winter wheat region of the United States were used to determine the composition and frequency of biotypes. The wheat cultivars \u27Seneca\u27 (H7Hs), \u27Monon\u27 (H3), \u27Knox 62\u27 (~, H7Hg), and \u27Abe\u27 (Hs) were used as differentials. Biotypes J and L replaced biotype B as the prevalent biotype in Indiana, since wheat cultivars having the Hs and the H6 genes have been grown. Biotype GP, the least virulent of any Hessian fly biotypes, was still present in New York indicating that wheat cuItivars with no genes for resistance are still being grown there. The genetic variability of Hessian fly biotypes that enables them to overcome the resistance in wheat cultivars is discussed
Discovery of 6.035GHz Hydroxyl Maser Flares in IRAS18566+0408
We report the discovery of 6.035GHz hydroxyl (OH) maser flares toward the
massive star forming region IRAS18566+0408 (G37.55+0.20), which is the only
region known to show periodic formaldehyde (4.8 GHz H2CO) and methanol (6.7 GHz
CH3OH) maser flares. The observations were conducted between October 2008 and
January 2010 with the 305m Arecibo Telescope in Puerto Rico. We detected two
flare events, one in March 2009, and one in September to November 2009. The OH
maser flares are not simultaneous with the H2CO flares, but may be correlated
with CH3OH flares from a component at corresponding velocities. A possible
correlated variability of OH and CH3OH masers in IRAS18566+0408 is consistent
with a common excitation mechanism (IR pumping) as predicted by theory.Comment: Accepted for publication in the Astrophysical Journa
Long-term Variability of HCO Masers in Star-forming Regions
We present results of a multi-epoch monitoring program on variability of
6cm formaldehyde (HCO) masers in the massive star forming region
NGC7538IRS1 from 2008 to 2015 conducted with the GBT, WSRT, and
VLA. We found that the similar variability behaviors of the two formaldehyde
maser velocity components in NGC7538IRS1 (which was pointed out by
Araya and collaborators in 2007) have continued. The possibility that the
variability is caused by changes in the maser amplification path in regions
with similar morphology and kinematics is discussed. We also observed
12.2GHz methanol and 22.2GHz water masers toward
NGC7538IRS1. The brightest maser components of CHOH and HO
species show a decrease in flux density as a function of time. The brightest
HCO maser component also shows a decrease in flux density and has a similar
LSR velocity to the brightest HO and 12.2GHz CHOH masers. The line
parameters of radio recombination lines and the 20.17 and 20.97GHz CHOH
transitions in NGC7538IRS1 are also reported. In addition, we
observed five other 6cm formaldehyde maser regions. We found no evidence of
significant variability of the 6cm masers in these regions with respect to
previous observations, the only possible exception being the maser in
G29.960.02. All six sources were also observed in the HCO
isotopologue transition of the 6cm HCO line; HCO absorption
was detected in five of the sources. Estimated column density ratios
[HCO]/[HCO] are reported.Comment: 29 pages, 9 figure
Conductivity fluctuations in polymer's networks
Polymer's network is treated as an anisotropic fractal with fractional
dimensionality D = 1 + \epsilon close to one. Percolation model on such a
fractal is studied. Using the real space renormalization group approach of
Migdal and Kadanoff we find threshold value and all the critical exponents to
be strongly nonanalytic functions of \epsilon, e.g. the critical exponent of
the conductivity was obtained to be \epsilon^{-2}\exp(-1-1/\epsilon). The main
part of the finite size conductivities distribution function at the threshold
was found to be universal if expressed in terms of the fluctuating variable,
which is proportional to the large power of the conductivity, but with
dimensionally-dependent low-conductivity cut-off. Its reduced central momenta
are of the order of \exp(-1/\epsilon) up to the very high order.Comment: 7 pages, one eps figure, uses epsf style, to be published in Proc. of
LEES-97 (Physica B
Weak and Compact Radio Emission in Early High-Mass Star Forming Regions: II. The Nature of the Radio Sources
In this study we analyze 70 radio continuum sources associated with dust
clumps and considered to be candidates for the earliest stages of high-mass
star formation. The detection of these sources was reported by Rosero et al.
(2016), who found most of them to show weak (1 mJy) and
compact (0.6) radio emission. Herein, we
used the observed parameters of these sources to investigate the origin of the
radio continuum emission. We found that at least of these radio
detections are most likely ionized jets associated with high-mass protostars,
but for the most compact sources we cannot discard the scenario that they
represent pressure-confined HII regions. This result is highly relevant for
recent theoretical models based on core accretion that predict the first stages
of ionization from high-mass stars to be in the form of jets. Additionally, we
found that properties such as the radio luminosity as a function of the
bolometric luminosity of ionized jets from low and high-mass stars are
extremely well-correlated. Our data improve upon previous studies by providing
further evidence of a common origin for jets independently of luminosity.Comment: Accepted for publication in the Ap
Weak and Compact Radio Emission in Early High-Mass Star Forming Regions: I. VLA Observations
We present a high sensitivity radio continuum survey at 6 and 1.3cm using
the Karl G. Jansky Very Large Array towards a sample of 58 high-mass star
forming regions. Our sample was chosen from dust clumps within infrared dark
clouds with and without IR sources (CMC-IRs, CMCs, respectively), and hot
molecular cores (HMCs), with no previous, or relatively weak radio continuum
detection at the mJy level. Due to the improvement in the continuum
sensitivity of the VLA, this survey achieved map rms levels of 3-10
Jy beam at sub-arcsecond angular resolution. We extracted 70
centimeter continuum sources associated with 1.2mm dust clumps. Most
sources are weak, compact, and are prime candidates for high-mass protostars.
Detection rates of radio sources associated with the mm dust clumps for CMCs,
CMC-IRs and HMCs are 6, 53 and 100, respectively. This result is
consistent with increasing high-mass star formation activity from CMCs to HMCs.
The radio sources located within HMCs and CMC-IRs occur close to the dust clump
centers with a median offset from it of 12,000AU and 4,000AU,
respectively. We calculated 5 - 25GHz spectral indices using power law fits
and obtain a median value of 0.5 (i.e., flux increasing with frequency),
suggestive of thermal emission from ionized jets. In this paper we describe the
sample, observations, and detections. The analysis and discussion will be
presented in Paper II.Comment: Accepted for publication in the ApJ
A New Galactic 6cm Formaldehyde Maser
We report the detection of a new H2CO maser in the massive star forming
region G23.71-0.20 (IRAS 18324-0820), i.e., the fifth region in the Galaxy
where H2CO maser emission has been found. The new H2CO maser is located toward
a compact HII region, and is coincident in velocity and position with 6.7 GHz
methanol masers and with an IR source as revealed by Spitzer/IRAC GLIMPSE data.
The coincidence with an IR source and 6.7 GHz methanol masers suggests that the
maser is in close proximity to an embedded massive protostar. Thus, the
detection of H2CO maser emission toward G23.71-0.20 supports the trend that
H2CO 6cm masers trace molecular material very near young massive stellar
objects.Comment: Accepted for publication in The Astrophysical Journal Letter
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