628 research outputs found
Big Game Cats and Defining Football’s Value: College Football’s Popularity, Controversies, and Expansion
This thesis directly approaches intercollegiate football from a cultural perspective. The football’s popularity exploded during the Twentieth-Century. Television, merchandizing, and a national sporting culture are associated with this development. However, controversies often muddied the waters of that popularity. Football’s brutality, athletic scholarships, and controversies within athletics departments overshadowed the immense popularity of intercollegiate football. During the Twenty-First Century, several universities started new football programs. Two of which being Georgia State University and Southeastern Louisiana University. Given the context balancing popularity and controversy, the administrators demonstrated how the image of intercollegiate football has changed over the course of the past century. This thesis analyzes how the administrators sold the new football programs to their respective institutions and concludes that both universities emphasized the sport’s popularity, avoided controversy, recognized the large potential for financial loss, and concentrated the new programs benefit being increased indirect and intrinsic values
Metatranscriptome of human faecal microbial communities in a cohort of adult men
The gut microbiome is intimately related to human health, but it is not yet known which functional activities are driven by specific microorganisms\u27 ecological configurations or transcription. We report a large-scale investigation of 372 human faecal metatranscriptomes and 929 metagenomes from a subset of 308 men in the Health Professionals Follow-Up Study. We identified a metatranscriptomic \u27core\u27 universally transcribed over time and across participants, often by different microorganisms. In contrast to the housekeeping functions enriched in this core, a \u27variable\u27 metatranscriptome included specialized pathways that were differentially expressed both across participants and among microorganisms. Finally, longitudinal metagenomic profiles allowed ecological interaction network reconstruction, which remained stable over the six-month timespan, as did strain tracking within and between participants. These results provide an initial characterization of human faecal microbial ecology into core, subject-specific, microorganism-specific and temporally variable transcription, and they differentiate metagenomically versus metatranscriptomically informative aspects of the human faecal microbiome
Feedback Systems for Linear Colliders
Feedback systems are essential for stable operation of a linear collider,
providing a cost-effective method for relaxing tight tolerances. In the
Stanford Linear Collider (SLC), feedback controls beam parameters such as
trajectory, energy, and intensity throughout the accelerator. A novel dithering
optimization system which adjusts final focus parameters to maximize luminosity
contributed to achieving record performance in the 1997-98 run. Performance
limitations of the steering feedback have been investigated, and improvements
have been made. For the Next Linear Collider (NLC), extensive feedback systems
are planned as an intregal part of the design. Feedback requiremetns for JLC
(the Japanese Linear Collider) are essentially identical to NLC; some of the
TESLA requirements are similar but there are significant differences. For NLC,
algorithms which incorporate improvements upon the SLC implementation are being
prototyped. Specialized systems for the damping rings, rf and interaction point
will operate at high bandwidth and fast response. To correct for the motion of
individual bunches within a train, both feedforward and feedback systems are
planned. SLC experience has shown that feedback systems are an invaluable
operational tool for decoupling systems, allowing precision tuning, and
providing pulse-to-pulse diagnostics. Feedback systems for the NLC will
incorporate the key SLC features and the benefits of advancing technologies.Comment: Invited talk presented at IEEE Particle Accelerator Conference
(PAC99
Stability of the human faecal microbiome in a cohort of adult men
Characterizing the stability of the gut microbiome is important to exploit it as a therapeutic target and diagnostic biomarker. We metagenomically and metatranscriptomically sequenced the faecal microbiomes of 308 participants in the Health Professionals Follow-Up Study. Participants provided four stool samples—one pair collected 24–72 h apart and a second pair ~6 months later. Within-person taxonomic and functional variation was consistently lower than between-person variation over time. In contrast, metatranscriptomic profiles were comparably variable within and between subjects due to higher within-subject longitudinal variation. Metagenomic instability accounted for ~74% of corresponding metatranscriptomic instability. The rest was probably attributable to sources such as regulation. Among the pathways that were differentially regulated, most were consistently over- or under-transcribed at each time point. Together, these results suggest that a single measurement of the faecal microbiome can provide long-term information regarding organismal composition and functional potential, but repeated or short-term measures may be necessary for dynamic features identified by metatranscriptomics
Recommended from our members
The trajectory control in the SLC linac
Due to wake field effects, the trajectories of accelerated beams in the Linac should be well maintained to avoid severe beam breakup. In order to maintain a small emittance at the end of the Linac, the tolerance on the trajectory deviations become tighter when the beam intensities increase. The existing two beam trajectory correction method works well when the theoretical model agrees with the real machine lattice. Unknown energy deviations along the linac as well as wake field effects can cause the real lattice to deviate from the model. This makes the trajectory correction difficult. Several automated procedures have been developed to solve these problems. They are: an automated procedure to frequently steer the whole Linac by dividing the Linac into several small regions; an automated procedure to empirically correct the model to fit the real lattice and eight trajectory correcting feedback loops along the linac and steering through the collimator region with restricted corrector strengths and a restricted number of correctors. 6 refs., 2 figs
Low-Level Nuclear Activity in Nearby Spiral Galaxies
We are conducting a search for supermassive black holes (SMBHs) with masses
below 10^7 M_sun by looking for signs of extremely low-level nuclear activity
in nearby galaxies that are not known to be AGNs. Our survey has the following
characteristics: (a) X-ray selection using the Chandra X-ray Observatory, since
x-rays are a ubiquitous feature of AGNs; (b) Emphasis on late-type spiral and
dwarf galaxies, as the galaxies most likely to have low-mass SMBHs; (c) Use of
multiwavelength data to verify the source is an AGN; and (d) Use of the highest
angular resolution available for observations in x-rays and other bands, to
separate nuclear from off-nuclear sources and to minimize contamination by host
galaxy light. Here we show the feasibility of this technique to find AGNs by
applying it to six nearby, face-on spiral galaxies (NGC 3169, NGC 3184, NGC
4102, NGC 4647, NGC 4713, NGC 5457) for which data already exist in the Chandra
archive. All six show nuclear x-ray sources. The data as they exist at present
are ambiguous regarding the nature of the nuclear x-ray sources in NGC 4713 and
NGC 4647. We conclude, in accord with previous studies, that NGC 3169 and NGC
4102 are almost certainly AGNs. Most interestingly, a strong argument can be
made that NGC 3184 and NGC 5457, both of type Scd, host AGNs.Comment: 37 pages, 10 figures, ApJ, in press. Replaced with accepted versio
Recommended from our members
Generalized fast feedback system in the SLC
A generalized fast feedback system has been developed to stabilize beams at various locations in the SLC. The system is designed to perform measurements and change actuator settings to control beam states such as position, angle and energy on a pulse to pulse basis. The software design is based on the state space formalism of digital control theory. The system is database-driven, facilitating the addition of new loops without requiring additional software. A communications system, KISNet, provides fast communications links between microprocessors for feedback loops which involve multiple micros. Feedback loops have been installed in seventeen locations throughout the SLC and have proven to be invaluable in stabilizing the machine
Suppression of secondary electron emission using triangular grooved surface in the ILC dipole and wiggler magnets
The development of an electron cloud in the vacuum chambers of high intensity positron and proton storage rings may limit machine performance. The suppression of electrons in a magnet is a challenge for the positron damping ring of the International Linear Collider (ILC) as well as the Large Hadron Collider. Simulation show that grooved surfaces can significantly reduce the electron yield in a magnet. Some of the secondary electrons emitted from the grooved surface return to the surface within a few gyrations, resulting in a low effective secondary electron yield (SEY) of below 1.0 A triangular surface is an effective, technologically attractive mitigation with a low SEY and a weak dependence on the scale of the corrugations and the external magnetic field. A chamber with triangular grooved surface is proposed for the dipole and wiggler sections of the ILC and will be tested in KEKB in 2007. The strategy of electron cloud control in ILC and the optimization of the grooved chamber such as the SEY, impedance as well as the manufacturing of the chamber, are also discussed
On the Particle Data Group evaluation of Psi' and chi_c Branching Ratios
I propose a new evaluation of and branching ratios
which avoids the correlations affecting the current Particle Data Group
evaluation.
These correlations explain the apparent technique-dependent discrepancies
between the available determinations of the
and under the hypotesis that the current
values of the branching ratios are
overestimated.
In the process I also noticed that Particle Data Group has not restated many
of the older measurements, when necessary, for the new value of , which significantly affects the evaluation of some
relevant and exclusive branching ratios.Comment: 13 pages. Revised version. Submitted to Phys. Rev.
- …