452 research outputs found
Product Design: A course in first principles
Professor Bonollo has crafted a text that aims at providing
introductory studies in product design which may be
undertaken in the early years of programs in industrial and
engineering design, design and technology and product
design engineering as studied in art and design schools,
polytechnics and universities. In scope, the book is
primarily about systematic, self-directed learning in design
Nome Day Shelter
The Nome Day Shelter was created in response to community needs due to weather- related exposure deaths, impoverished community members, homelessness, hospital emergency department interactions, and various presentations of public social maladies. Although the protection of women was not the primary purpose in the establishment of the Day Shelter, this factor is a significant by-product of this sanctuary. An accurate accounting of MMIWG does not exist in the Norton Sound region. It may be reasonably inferred safety the Shelter provides has an impact on MMIWG in the Bering Strait region
\u3ci\u3eAPOE\u3c/i\u3e Genetics Influence Murine Gut Microbiome
Apolipoprotein E (APOE) alleles impact pathogenesis and risk for multiple human diseases, making them primary targets for disease treatment and prevention. Previously, we and others reported an association between APOE alleles and the gut microbiome. Here, we evaluated effects of APOE heterozygosity and tested whether these overall results extended to mice maintained under ideal conditions for microbiome analyses. To model human APOE alleles, this study used APOE targeted replacement (TR) mice on a C57Bl/6 background. To minimize genetic drift, homozygous APOE3 mice were crossed to homozygous APOE2 or homozygous APOE4 mice prior to the study, and the resulting heterozygous progeny crossed further to generate the study mice. To maximize environmental homogeneity, mice with mixed genotypes were housed together and used bedding from the cages was mixed and added back as a portion of new bedding. Fecal samples were obtained from mice at 3-, 5- and 7-months of age, and microbiota analyzed by 16S ribosomal RNA gene amplicon sequencing. Linear discriminant analysis of effect size (LefSe) identified taxa associated with APOE status, depicted as cladograms to show phylogenetic relatedness. The influence of APOE status was tested on alpha-diversity (Shannon H index) and beta-diversity (principal coordinate analyses and PERMANOVA). Individual taxa associated with APOE status were identified by classical univariate analysis. Whether findings in the APOE mice were replicated in humans was evaluated by using published microbiome genome wide association data. Cladograms revealed robust differences with APOE in male mice and limited differences in female mice. The richness and evenness (alpha-diversity) and microbial community composition (beta-diversity) of the fecal microbiome was robustly associated with APOE status in male but not female mice. Classical univariate analysis revealed individual taxa that were significantly increased or decreased with APOE, illustrating a stepwise APOE2-APOE3–APOE4 pattern of association with heterozygous animals trending as intermediate in the stepwise pattern. The relative abundance of bacteria from the class Clostridia, order Clostridiales, family Ruminococacceae and related genera increased with APOE2 status. The relative abundance of Erysipelotrichia increased with APOE4 status, a finding that extended to humans. In this study, wherein mice were maintained in an ideal fashion for microbiome studies, gut microbiome profiles were strongly and significantly associated with APOE status in male APOE-TR mice. Erysipelotrichia are increased with APOE4 in both mice and humans. APOE allelic effects appeared generally intermediate in heterozygous animals. Further evaluation of these findings in humans, as well as studies evaluating the impact of the APOE-associated microbiota on disease-relevant phenotypes, will be necessary to determine if alterations in the gut microbiome represent a novel mechanism whereby APOE alleles impact disease
On real one-sided ideals in a free algebra
In classical and real algebraic geometry there are several notions of the
radical of an ideal I. There is the vanishing radical defined as the set of all
real polynomials vanishing on the real zero set of I, and the real radical
defined as the smallest real ideal containing I. By the real Nullstellensatz
they coincide. This paper focuses on extensions of these to the free algebra
R of noncommutative real polynomials in x=(x_1,...,x_g) and
x^*=(x_1^*,...,x_g^*).
We work with a natural notion of the (noncommutative real) zero set V(I) of a
left ideal I in the free algebra. The vanishing radical of I is the set of all
noncommutative polynomials p which vanish on V(I). In this paper our quest is
to find classes of left ideals I which coincide with their vanishing radical.
We completely succeed for monomial ideals and homogeneous principal ideals. We
also present the case of principal univariate ideals with a degree two
generator and find that it is very messy. Also we give an algorithm (running
under NCAlgebra) which checks if a left ideal is radical or is not, and
illustrate how one uses our implementation of it.Comment: v1: 31 pages; v2: 32 page
R^4 counterterm and E7(7) symmetry in maximal supergravity
The coefficient of a potential R^4 counterterm in N=8 supergravity has been
shown previously to vanish in an explicit three-loop calculation. The R^4 term
respects N=8 supersymmetry; hence this result poses the question of whether
another symmetry could be responsible for the cancellation of the three-loop
divergence. In this article we investigate possible restrictions from the coset
symmetry E7(7)/SU(8), exploring the limits as a single scalar becomes soft, as
well as a double-soft scalar limit relation derived recently by Arkani-Hamed et
al. We implement these relations for the matrix elements of the R^4 term that
occurs in the low-energy expansion of closed-string tree-level amplitudes. We
find that the matrix elements of R^4 that we investigated all obey the
double-soft scalar limit relation, including certain
non-maximally-helicity-violating six-point amplitudes. However, the single-soft
limit does not vanish for this latter set of amplitudes, which suggests that
the E7(7) symmetry is broken by the R^4 term.Comment: 33 pages, typos corrected, published versio
The host galaxies of luminous quasars
We present results of a deep HST/WFPC2 imaging study of 17 quasars at z~0.4,
designed to determine the properties of their host galaxies. The sample
consists of quasars with absolute magnitudes in the range -24>M_V>-28, allowing
us to investigate host galaxy properties across a decade in quasar luminosity,
but at a single redshift. We find that the hosts of all the RLQs, and all the
RQQs with nuclear luminosities M_V<-24, are massive bulge-dominated galaxies,
confirming and extending the trends deduced from our previous studies. From the
best-fitting model host galaxies we have estimated spheroid and black-hole
masses, and the efficiency (with respect to Eddington luminosity) with which
each quasar is radiating. The largest inferred black-hole mass in our sample is
\~3.10^9 M_sun, comparable to those at the centres of M87 and Cygnus A. We find
no evidence for super-Eddington accretion in even the most luminous objects. We
investigate the role of scatter in the black-hole:spheroid mass relation in
determining the ratio of quasar to host-galaxy luminosity, by generating
simulated populations of quasars lying in hosts with a Schechter mass function.
Within the subsample of the highest luminosity quasars, the observed variation
in nuclear-host luminosity ratio is consistent with being the result of the
scatter in the black-hole:spheroid relation. Quasars with high nuclear-host
ratios can be explained by sub-Eddington accretion onto black holes in the
high-mass tail of the black-hole:spheroid relation. Our results imply that,
owing to the Schechter cutoff, host mass should not continue to increase
linearly with quasar luminosity, at the very highest luminosities. Any quasars
more luminous than M_V=-27 should be found in massive elliptical hosts which at
the present day would have M_V ~ -24.5.Comment: Accepted for publication in MNRAS. 18 pages; 7 figures and 17
greyscale images are reproduced here at low quality due to space limitations.
High-resolution figures are available from
ftp://ftp.roe.ac.uk/pub/djef/preprints/floyd2004
One-Loop n-Point Gauge Theory Amplitudes, Unitarity and Collinear Limits
We present a technique which utilizes unitarity and collinear limits to
construct ansatze for one-loop amplitudes in gauge theory. As an example, we
obtain the one-loop contribution to amplitudes for gluon scattering in
supersymmetric Yang-Mills theory with the helicity configuration of the
Parke-Taylor tree amplitudes. We prove that our ansatz is correct using
general properties of the relevant one-loop -point integrals. We also give
the ``splitting amplitudes'' which govern the collinear behavior of one-loop
helicity amplitudes in gauge theories.Comment: 52 pages (including figures), minor typographical errors corrected,
SLAC-PUB-641
Comparison of the efficacy of four drug combinations for immobilization of wild pigs
Field immobilization of native or invasive wild pigs (Sus scrofa) is challenging. Drug combinations commonly used often result in unsatisfactory immobilization, poor recovery, and adverse side effects, leading to unsafe handling conditions for both animals and humans. We compared four chemical immobilization combinations, medetomidine–midazolam–butorphanol (MMB), butorphanol–azaperone–medetomidine (BAM™), nalbuphine–medetomidine–azaperone (NalMed-A), and tiletamine– zolazepam–xylazine (TZX), to determine which drug combinations might provide better chemical immobilization of wild pigs. We achieved adequate immobilization with no post-recovery morbidity withMMB. Adequate immobilization was achieved with BAM™; however, we observed post-recovery morbidity. Both MMB and BAM™ produced more optimal results relative to body temperature, recovery, and post-recovery morbidity and mortality compared to TZX. Adequate immobilization was not achieved with NalMed-A. Of the four drug combinations examined, we conclude that MMB performed most optimally for immobilization and recovery of wild pigs
Field Blue Stragglers and Related Mass Transfer Issues
This chapter contains my impressions and perspectives about the current state
of knowledge about field blue stragglers (FBS) stars, drawn from an extensive
literature that I searched. I conclude my review of issues that attend FBS and
mass transfer, by a brief enumeration of a few mildly disquieting observational
facts.Comment: Chapter 4, in Ecology of Blue Straggler Stars, H.M.J. Boffin, G.
Carraro & G. Beccari (Eds), Astrophysics and Space Science Library, Springe
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