5,553 research outputs found
Nearby Gas-Rich Low Surface Brightness Galaxies
We examine the Fisher-Tully cz<1000 km/s galaxy sample to determine whether
it is a complete and representative sample of all galaxy types, including low
surface brightness populations, as has been recently claimed. We find that the
sample is progressively more incomplete for galaxies with (1) smaller physical
diameters at a fixed isophote and (2) lower HI masses. This is likely to lead
to a significant undercounting of nearby gas-rich low surface brightness
galaxies. However, through comparisons to other samples we can understand how
the nearby galaxy counts need to be corrected, and we see some indications of
environmental effects that probably result from the local high density of
galaxies.Comment: 12 page, 2 figures, to appear in Ap
Understanding the effect of oxidative and ER stress on CHO cell culture and product quality through multivariate analysis
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Design and Performance of Arena Dam
Arena Dam is located in north-central Trinidad, West Indies. The dam forms a 35,000-acre-foot reservoir, which serves as the main raw water storage facility for Trinidad. The 1.6-million-cubic-yard earthfill embankment has a crest elevation 80 feet above the original streambed. The upstream-sloping core is composed of dispersive clay. The shells are composed of compacted fine sand and silty fine sand. The dam is founded on deep, stiff, fissured clay deposits interbedded with sand. The project is located approximately 12 miles from the El Pilar Fault, a major Caribbean fault with seismic activity comparable to that of the San Andreas Fault in the United States. Important design concerns included the dispersive clay core, residual strength properties of the foundation, embankment and control structure settlement, and the seismic environment. This paper discusses the design criteria and approach, and field performance data from foundation and embankment piezometers and survey monuments in the outlet conduit
Observing the Symmetry of Attractors
We show how the symmetry of attractors of equivariant dynamical systems can
be observed by equivariant projections of the phase space. Equivariant
projections have long been used, but they can give misleading results if used
improperly and have been considered untrustworthy. We find conditions under
which an equivariant projection generically shows the correct symmetry of the
attractor.Comment: 28 page LaTeX document with 9 ps figures included. Supplementary
color figures available at http://odin.math.nau.edu/~jws
PSEUDOMONAS AVR AND HOP PROTEINS, THEIR ENCODING NUCLEIC ACIDS, AND USE THEREOF
One aspect of the present invention relates to isolated nucleic acid molecules encoding avirulence proteins or polypeptides of Pseudomonas syringae pv. syringae DC 3000, or nucleic acid moleculues which are complementary thereto. Expression vectors, host cells, and transgenic plants which include the DNA molecules of the present invention are also disclosed. Another aspect relates to the isolated proteins or polypeptides and compositions containing the same. The various nucleic acid molecules and proteins of the present invention can be used to impart disease resistance to a plant, make a plant hypersusceptible to colonization by nonpathogenic bacteria, modify a metabolic pathway in a cell, cause eukaryotic cell death and treat a cancerous condition, as well as inhibit programmed cell death
Cosmic homogeneity demonstrated with luminous red galaxies
We test the homogeneity of the Universe at with the Luminous Red
Galaxy (LRG) spectroscopic sample of the Sloan Digital Sky Survey. First, the
mean number of LRGs within completely surveyed LRG-centered spheres of
comoving radius is shown to be proportional to at radii greater than
. The test has the virtue that it does not rely
on the assumption that the LRG sample has a finite mean density; its results
show, however, that there \emph{is} such a mean density. Secondly, the survey
sky area is divided into 10 disjoint solid angular regions and the fractional
rms density variations of the LRG sample in the redshift range
among these () regions is found to be 7
percent of the mean density. This variance is consistent with typical biased
\lcdm models and puts very strong constraints on the quality of SDSS
photometric calibration.Comment: submitted to Ap
Factors Affecting Retention of Undergraduate Students in Fisheries and Wildlife Programs
Undergraduate enrollment in agriculture and natural resources‐related programs has steadily declined for the past decade or more. College administrators and faculty struggle to separate the real causes of this decline from the superficial and often mythical factors. How programs should address this decline is of similar concern. Rather than speculate on why students do not pursue a degree in a natural resources field, specifically fisheries and wildlife (FW), we decided to investigate the question of FW student retention from the perspective of the students themselves. Specifically, we wanted to know: (a) Why do students say they chose to leave the FW program at MSU? (b) Why did students who persisted in program say they chose to stay? and (c) What reasons did transfer students give for choosing FW as a major? We conducted a series of face‐to‐face interviews with these three groups of students, and asked them a series of 10‐14 questions related to their experiences in the Department of Fisheries and Wildlife at Michigan State University in an effort to better understand student reasons for leaving, persisting, and immigrating into the program. Although our project is just beginning, preliminary results offer some interesting insights into the departure puzzle. Specific, but limited, findings from interviewees include: (a) the importance of job prospects and earnings potential, (b) a general reluctance to pursue postgraduate education, (c) a degree of disillusionment at the relative lack of outdoor experiences offered by the program in classroom and extracurricular activities, and (d) a desire for more active participation and field experiences in the undergraduate program. Several students in this study told us that they selected FW out of a desire to spend more time in the field, and were disappointed this was frequently not the case. Some students expressed a general feeling of deception at the realities of the departmental curriculum, although these were poorly defined and may be the product of other issues such as unrealistic program expectations. This ongoing study has the potential to inform natural resource programs on techniques to attract, retain, and educate undergraduate students
Visual motherese? Signal-to-noise ratios in toddler-directed television
Younger brains are noisier information processing systems; this means that information for younger individuals has to allow clearer differentiation between those aspects that are required for the processing task in hand (the ‘signal’) and those that are not (the ‘noise’). We compared toddler-directed and adult-directed TV programmes (TotTV/ATV). We examined how low-level visual features (that previous research has suggested influence gaze allocation) relate to semantic information, namely the location of the character speaking in each frame. We show that this relationship differs between TotTV and ATV. First, we conducted Receiver Operator Characteristics analyses and found that feature congestion predicted speaking character location in TotTV but not ATV. Second, we used multiple analytical strategies to show that luminance differentials (flicker) predict face location more strongly in TotTV than ATV. Our results suggest that TotTV designers have intuited techniques for controlling toddler attention using low-level visual cues. The implications of these findings for structuring childhood learning experiences away from a screen are discussed
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