13,530 research outputs found
Prevalencia de erliquiosis monocítica canina en ciudad de Juárez, Chihuahua durante los meses de mayo de 2005 a abril de 2006
The quest for corporate growth
Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1996.Includes bibliographical references (leaves 116-122).by Gabriel D. Obrador Ramos and Edmundo E. Ruiz Rodriguez.M.S
A Chemical Map of the Outbursting V883 Ori system: Vertical and Radial Structures
We present the first results of a pilot program to conduct an Atacama Large
Millimeter/submillimeter Array (ALMA) Band 6 (211-275 GHz) spectral line study
of young stellar objects (YSO) that are undergoing rapid accretion episodes,
i.e. FU Ori objects (FUors). Here, we report on molecular emission line
observations of the FUor system, V883 Ori. In order to image the FUor object
with full coverage from ~0.5 arcsec to the map size of ~30 arcsec, i.e. from
disc to outflow scales, we combine the ALMA main array (the 12-m array) with
the Atacama Compact Array (7-m array) and the total power (TP) array. We detect
HCN, HCO, CHOH, SO, DCN, and HCO emissions with most of these
lines displaying complex kinematics. From PV diagrams, the detected molecules
HCN, HCO, CHOH, DCN, SO, and HCO probe a Keplerian rotating
disc in a direction perpendicular to the large-scale outflow detected
previously with the CO and CO lines. Additionally, HCN and
HCO reveal kinematic signatures of infall motion. The north outflow is
seen in HCO, HCO, and SO emissions. Interestingly, HCO
emission reveals a pronounced inner depression or "hole" with a size comparable
to the radial extension estimated for the CHOH and 230 GHz continuum. The
inner depression in the integrated HCO intensity distribution of V883 Ori
is most likely the result of optical depth effects, wherein the optically thick
nature of the HCO and continuum emission towards the innermost parts of
V883 Ori can result in a continuum subtraction artifact in the final HCO
flux level
240: Reduced-intensity stem cell transplantation in patients with high-risk acute lymphoblastic leukemia (ALL)
Multiobjective simulation optimization in software project management
Traditionally, simulation has been used by project managers
in optimising decision making. However, current simulation
packages only include simulation optimisation which considers
a single objective (or multiple objectives combined
into a single fitness function). This paper aims to describe
an approach that consists of using multiobjective optimisation
techniques via simulation in order to help software
project managers find the best values for initial team size
and schedule estimates for a given project so that cost, time
and productivity are optimised. Using a System Dynamics
(SD) simulation model of a software project, the sensitivity
of the output variables regarding productivity, cost and
schedule using different initial team size and schedule estimations
is determined. The generated data is combined
with a well-known multiobjective optimisation algorithm,
NSGA-II, to find optimal solutions for the output variables.
The NSGA-II algorithm was able to quickly converge to a
set of optimal solutions composed of multiple and conflicting
variables from a medium size software project simulation
model. Multiobjective optimisation and SD simulation
modeling are complementary techniques that can generate
the Pareto front needed by project managers for decision
making. Furthermore, visual representations of such solutions
are intuitive and can help project managers in their
decision making process
Preparation of Dipteran Larvae for Scanning Electron Microscopy with Special Reference to Myiasigen Dipteran Species
Although controversy exists concerning the role of chemical fixatives in scanning electron microscopy (SEM) studies of Dipteran larvae, we have observed that filtered 10% formaldehyde solution gives excellent results as a preservative. After immersing in vivo in formaldehyde, the larvae material is preserved for prolonged periods (up to 8 months), before examination with SEM. As a fixative, formaldehyde preserves the structure of the larval cuticle and produces no visible artifacts. Moreover, postfixation is not necessary.
Due to pecularities of the way of life of Wohlfahrtia magnifica (principally the accumulations of necrotic tissue, purulent particles, and other types of substances that often adhere to the numerous spines of larvae), this species must be cleaned before examination by SEM. Manual cleaning with alternating bidistilled water and 0.9% saline solution proved to be a rapid, easy and inexpensive method that gave good results.
Both lyophilization drying and critical point drying were used before sputtering the material. While lyophilization drying proved to be the most effective method for instars II and III, critical point drying was the best technique for study of specimens belonging to instar I. The optimum time for drying and conditions for lyophilization and sputter-coating with gold were determined experimentally. Samples were mounted on SEM stubs with double-sided adhesive and silver conductive paint.
The method proposed is easy and effective for the SEM study of larvae myiasis-producing diptera
Updated comparison of age estimates from paired calcified structures from Atlantic bluefin tuna
In this paper we present an updated comparison of age estimates from otoliths and spines
from the same specimen, with the intention to analyze whether it is possible to use both
structures in obtaining age-length keys for this species. The agreement between otolith and
spine age estimates was good for bluefin tuna younger than 14 years old with less than one
year difference. Tests of symmetry showed the asymmetrical distribution of ages. However
no significant differences were found between the growth parameters estimated from both
paired hard parts. It is suggested using both structures readings for constructing agelength
keys for bluefin tuna younger than 14 years.En prensa0,000
Science with an ngVLA: Resolving the Radio Complexity of EXor and FUor-type Systems with the ngVLA
Episodic accretion may be a common occurrence in the evolution of young
pre-main sequence stars and has important implications for our understanding of
star and planet formation. Many fundamental aspects of what drives the
accretion physics, however, are still unknown. The ngVLA will be a key tool in
understanding the nature of these events. The high spatial resolution, broad
spectral coverage, and unprecedented sensitivity will allow for the detailed
analysis of outburst systems. The proposed frequency range of the ngVLA allows
for observations of the gas, dust, and non-thermal emission from the star and
disk.Comment: 8 pages, 1 figure, To be published in the ASP Monograph Series,
"Science with a Next-Generation VLA", ed. E. J. Murphy (ASP, San Francisco,
CA
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