22,938 research outputs found
Modified spiral wound retaining ring
A spiral wound retaining ring with angled ends is described. The ring is crimped at the same angle as the ring ends to maintain a constant thickness dimension. The angling of the ends of the ring and crimp allow the ends to be positioned closer together while maintaining enough clearance to enable insertion and removal of the ring. By reducing the separation distance between the ends a stronger ring results since the double layer area of the ring is maximized
A study of some aspects of growth and reproduction in two inbred lines of mice and their crosses : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Massey University of Manawatu
The mating of closely related individuals is generally believed to result in inferior offspring. Recognition of this danger has been suggested as the reason for evolution of human social customs. However, historical researches suggest that inbreeding unavoidably occurred in small, isolated, ancient communities, and marriage of close relatives was encouraged in the Egyptian, Greek and Hebrew civilisations (Zirkle, 1952).
Inbreeding is likely to have occurred in the isolated flocks of nomads, but it is probable that inbreeding depression, as such, was not recognised until the eighteenth century when the early livestock improvers are reputed to have found that the fertility of their animals deteriorated with continued inbreeding.
Hybrid vigour from cross breeding plants was described by Koelreuter (1766)
and confirmed by later botanists., .After much detailed work, Darwin (1876) concluded:
" •••cross fertilisation is generally beneficial and self
fertilisation injurious." and that
(a) Mechanisms exist widely for the avoidance of inbreeding.
(b) Inbreeding has effects likely to incur selective disadvantages.
No suitable hypothesis could account for the usually deleterious effects of inbreeding, or the reverse phenomenon of hybrid vigour until the rediscovery of Mendel's work in 1900. The effects of inbreeding can now be explained in terms of the dominance and recessiveness of genes. (Falconer, 1960).
The aim of experiments reported in this thesis was to study growth, reproduction and mortality in two inbred lines of mice, derived from common ancestors, to find if differences between them had arisen during inbreeding.
Reciprocal crosses and matings of the F1 progeny of these crosses were made to
find if hybridisation of the parent lines led to improvements of these charactÂeristics.
This study was suggested by Drs. D.S.. Flux, M.F. McDonald and R.E. Munford to whom the author is indebted for advice and guidance.
The author also wishes to acknowledge the assistance of Mr. E. Ormsby in histological preparations, of Mr. P .S. Dale in photomicrography, and of
Mr. C. Muir who drew some of the figures reproduced in this thesis. Thanks are also due to the staff of the University Library for their efforts in obtaining literature. [From Preface
Ironing out the details: Untangling dietary iron and genetic background in diabetes
The search for genetic risk factors in type-II diabetes has been hindered by a failure to consider dietary variables. Dietary nutrients impact metabolic disease risk and severity and are essential to maintaining metabolic health. Genetic variation between individuals confers differences in metabolism, which directly impacts response to diet. Most studies attempting to identify genetic risk factors in disease fail to incorporate dietary components, and thus are ill-equipped to capture the breadth of the genome’s impact on metabolism. Understanding how genetic background interacts with nutrients holds the key to predicting and preventing metabolic diseases through the implementation of personalized nutrition. Dysregulation of iron homeostasis is associated with type-II diabetes, but the link between dietary iron and metabolic dysfunction is poorly defined. High iron burden in adipose tissue induces insulin resistance, but the mechanisms underlying adipose iron accumulation remain unknown. Hepcidin controls dietary iron absorption and distribution in metabolic tissues, but it is unknown whether genetic variation influencing hepcidin expression modifies susceptibility to dietary iron-induced insulin resistance. This review highlights discoveries concerning the axis of iron homeostasis and adipose function and suggests that genetic variation underlying dietary iron metabolism is an understudied component of metabolic disease
Tarski monoids: Matui's spatial realization theorem
We introduce a class of inverse monoids, called Tarski monoids, that can be
regarded as non-commutative generalizations of the unique countable, atomless
Boolean algebra. These inverse monoids are related to a class of etale
topological groupoids under a non-commutative generalization of classical Stone
duality and, significantly, they arise naturally in the theory of dynamical
systems as developed by Matui. We are thereby able to reinterpret a theorem of
Matui on a class of \'etale groupoids as an equivalent theorem about a class of
Tarski monoids: two simple Tarski monoids are isomorphic if and only if their
groups of units are isomorphic. The inverse monoids in question may also be
viewed as countably infinite generalizations of finite symmetric inverse
monoids. Their groups of units therefore generalize the finite symmetric groups
and include amongst their number the classical Thompson groups.Comment: arXiv admin note: text overlap with arXiv:1407.147
Salsa Dance and Perceived Mental Health Benefits: A Servant Leadership Theory-Driven Study
The purpose of the current study was to assess servant leadership dimensions, perceived mental health benefits, and correlations between the two following an eight-week servant leadership theory-driven salsa dance programme taught to novice learners at a West Midlands, UK university. Upon completion of the salsa dance programme (frequency – once per week, intensity – moderate-to-vigorous physical activity, time – 90 minutes, type – group-based Cuban style salsa dance), a paper questionnaire was administered to the participants to complete in person. The questionnaire contained 18 items related to servant leadership dimensions (authenticity, empowerment, humility, standing back, and stewardship) in terms of the teaching and learning of salsa dance and four items related to perceived mental health benefits (mood enhancement, self-confidence, skill mastery, and social well-being). Authenticity and stewardship were rated higher in females when compared to males. Differences were found between perceived mental health benefits in both females and males with mood enhancement rated highest in both genders. This is the first study we are aware of to have applied principles of servant leadership in the teaching of salsa dance as a leisure-time physical activity. Servant leadership may have facilitated the high perceived mental health benefits observed
Virginia\u27s Money Follows the Person Demonstration
Educational Objectives
1. Describe Virginia\u27s Money Follows the Person Demonstration project, including the new services available to individuals through Virginia\u27s Medicaid-funded home and community-based waiver program.
2. Explain how Virginia\u27s Money Follows the Person Demonstration project, being administered by the Virginia Department of Medical Assistance Services (DMAS), would assist an individual in transitioning from a long-term care facility to the community.
3. Illustrate how someone might experience the MFP processes from pre-transition through post-transition
New low-mass members of the Octans stellar association and an updated 30-40 Myr lithium age
The Octans association is one of several young stellar moving groups recently
discovered in the Solar neighbourhood, and hence a valuable laboratory for
studies of stellar, circumstellar disc and planetary evolution. However, a lack
of low-mass members or any members with trigonometric parallaxes means the age,
distance and space motion of the group are poorly constrained. To better
determine its membership and age, we present the first spectroscopic survey for
new K and M-type Octans members, resulting in the discovery of 29 UV-bright
K5-M4 stars with kinematics, photometry and distances consistent with existing
members. Nine new members possess strong Li I absorption, which allow us to
estimate a lithium age of 30-40 Myr, similar to that of the Tucana-Horologium
association and bracketed by the firm lithium depletion boundary ages of the
Beta Pictoris (20 Myr) and Argus/IC 2391 (50 Myr) associations. Several stars
also show hints in our medium-resolution spectra of fast rotation or
spectroscopic binarity. More so than other nearby associations, Octans is much
larger than its age and internal velocity dispersion imply. It may be the
dispersing remnant of a sparse, extended structure which includes some younger
members of the foreground Octans-Near association recently proposed by
Zuckerman and collaborators.Comment: Accepted for publication in MNRAS (16 pages, 5 tables
The distribution of chlorophyll in the western Indian Ocean during the northeast monsoon period, February 13-July 16, 1965
This report contains the observations of phytoplankton pigment characteristics made during ATLANTIS II Cruise No. 15 in the western Indian Ocean and its reaches during the period of February 13 through July 16, 1965. As pointed out in a previous report for this region (Laird et al., 1964), the observations should by no means be considered synoptic since short-term variation will occur in biological measurements. The value of the present observations is greatly enhanced by the fact that they repeat and extend the previous data from ATLANTIS II Cruise No. 8 for the area, but are taken at the opposite period of the year for all regions. The data permit only a first approximation of the relative fertility in the area, yet the seasonal contrast becomes an important consideration in the analysis and interpretation of the data. It is believed that this represents the first such large-scale survey for Indian Ocean waters.The National Science Foundation under Grant NSF-GP 82
- …