4,189 research outputs found
INDICATORS OF INHABITANT, HOUSEHOLD, FAMILY AND ECONOMIC GROWTH: SOUTH CAROLINA AND NORTH CAROLINA
Social and economic futures are dependent on numbers of housing units, families, households and individuals, and on many characteristics of aggregate populations. Research reported in this manuscript is focused on the states of North Carolina and South Carolina and the counties therein. The chief concern is change; e.g., numerical and percentage increase or decrease. These dynamics refer to basic components of population: births, deaths and residential relocation.Consumer/Household Economics,
Improving the viability of mental models held by novice programmers
Recent research has found that many novice programmers often hold non-viable mental models of basic programming concepts such as assignment and object reference. This paper proposes a constructivist-based teaching model, integrating a cognitive conflict strategy with program visualization, with the aim of improving novice programmers’ mental models. The results of a preliminary empirical study suggest that, for the relatively straightforward concept of assignment, tight integration of program visualization with a cognitive conflict event that highlights a student’s inappropriate understanding can help improve students’ non-viable mental models. 14 out of 18 participants who held non-viable mental models of the assignment process successfully changed their model to be viable as a result of the proposed teaching model
Foray search: An effective systematic dispersal strategy in fragmented landscapes
In the absence of evidence to the contrary, population models generally assume that the dispersal trajectories of animals are random, but systematic dispersal could be more efficient at detecting new habitat and may therefore constitute a more realistic assumption. Here, we investigate, by means of simulations, the properties of a potentially widespread systematic dispersal strategy termed "foray search." Foray search was more efficient in detecting suitable habitat than was random dispersal in most landscapes and was less subject to energetic constraints. However, it also resulted in considerably shorter net dispersed distances and higher mortality per net dispersed distance than did random dispersal, and it would therefore be likely to lead to lower dispersal rates toward the margins of population networks. Consequently, the use of foray search by dispersers could crucially affect the extinction-colonization balance of metapopulations and the evolution of dispersal rates. We conclude that population models need to take the dispersal trajectories of individuals into account in order to make reliable predictions
Non-random dispersal in the butterfly Maniola jurtina: implications for metapopulation models
The dispersal patterns of animals are important in metapopulation ecology because they affect the dynamics and survival of populations. Theoretical models assume random dispersal but little is known in practice about the dispersal behaviour of individual animals or the strategy by which dispersers locate distant habitat patches. In the present study, we released individual meadow brown butterflies (Maniola jurtina) in a non-habitat and investigated their ability to return to a suitable habitat. The results provided three reasons for supposing that meadow brown butterflies do not seek habitat by means of random flight. First, when released within the range of their normal dispersal distances, the butterflies orientated towards suitable habitat at a higher rate than expected at random. Second, when released at larger distances from their habitat, they used a non-random, systematic, search strategy in which they flew in loops around the release point and returned periodically to it. Third, butterflies returned to a familiar habitat patch rather than a non-familiar one when given a choice. If dispersers actively orientate towards or search systematically for distant habitat, this may be problematic for existing metapopulation models, including models of the evolution of dispersal rates in metapopulations
MOLECULAR BASIS AND MODIFICATION OF A NEURAL CREST DEFICIT IN A DOWN SYNDROME MOUSE MODEL
poster abstractTrisomy 21 occurs in 1/700 live births and leads to phenotypes associat-ed with Down syndrome (DS), including craniofacial dysmorphology and a small mandible. Ts65Dn mice are trisomic for approximately half the genes on human chromosome 21 and display DS-like craniofacial anomalies. Cells cultured from Ts65Dn and euploid 1st pharyngeal arch (PA1) and neural tube (NT) tissues were used to analyze the effects of genetic dysregulation on cell proliferation and migration. In vitro studies revealed a proliferation deficit in trisomic PA1 and migration deficits from trisomic NT originating at embryonic day 9.5 (E9.5). DYRK1A is a gene thought to be involved in DS craniofacial development and we hypothesized that dysregulation of Dyrk1a contributes to altered craniofacial development in Ts65Dn mice. We also hypothesized that Dyrk1a agonists could be used to ameliorate this phenotype. To test our hypotheses, we quantified expression of Dyrk1a using qPCR. At E9.5, Dyrk1a is upregulated in Ts65Dn as relative to euploid PA1. We also showed that cell proliferation and migration could be returned to near euploid levels with the green tea polyphenol epigallocatechin gallate (EGCG) and harmine (known Dyrk1a inhibitors) in vitro. To further test our hypothesis, pregnant Ts65Dn and euploid mothers were treated with EGCG on E7 and E8 and E9.5 trisomic and euploid embryos were assessed for embryonic volume, PA1 vol-ume, and NCC number. Preliminary evidence suggests in vivo treatment leads to an increase in embryonic volume, PA1 volume, and NCC number in both euploid and trisomic embryos. Trisomic EGCG-treated embryos had similar PA1 volumes and NCC numbers to euploid embryos treated with PBS. Gene expression analysis of EGCG-treated NCCs is currently underway to better understand the effects of EGCG in these studies. Our results provide information about the molecular basis of DS craniofacial abnormalities and may lead to evidenced-based therapeutic options
HFPK 334: An unusual Supernova Remnant in the Small Magellanic Cloud
We present new Australia Telescope Compact Array (ATCA) radio-continuum and
XMM-Newton/Chandra X-ray Observatory (CXO) observations of the unusual
supernova remnant HFPK 334 in the Small Magellanic Cloud (SMC). The remnant
follows a shell type morphology in the radio-continuum and has a size of
20~pc at the SMC distance. The X-ray morphology is similar, however, we
detect a prominent point source close to the center of the SNR exhibiting a
spectrum with a best fit powerlaw with a photon index of . This central point source is most likely a background object and cannot
be directly associated with the remnant. The high temperature, nonequilibrium
conditions in the diffuse region suggest that this gas has been recently
shocked and point toward a younger SNR with an age of years.
With an average radio spectral index of we find that an
equipartition magnetic field for the remnant is 90~G, a value
typical of younger SNRs in low-density environments. Also, we report detection
of scattered radio polarisation across the remnant at 20~cm, with a peak
fractional polarisation level of 255\%.Comment: 19 pages, 6-figures, submitted to A
Health needs assessment for ex-Armed Forces personnel
Liverpool Health Observatory (LPHO) was commissioned to undertake a health needs assessment (HNA) for ex-Armed Forces personnel, and their families, in Cheshire and on Merseyside. The HNA focuses on personnel aged under 65. It includes a brief review of relevant literature, as well as a description of provision for ex-Armed Forces personnel at a local and national level
Fixed odds betting terminal use and problem gambling across the Liverpool City region
Liverpool Public Health Observatory was commissioned to look at problem gambling, and Fixed Odds Betting Terminal (FOBT) use, across the Liverpool City Region. The aims of the project were to develop a local evidence base in relation to FOBT use and problem gambling, look at reasons for excess gambling, and to investigate the availability and adequacy of local support services for problem gamblers. The project included an online survey on FOBT use, licensing officer visits to Licensed Betting Offices across the region, as well as interviews with problem gamblers, and staff working with them, across the region
TREATMENT OF CRANIOFACIAL DEFICITS ASSOCIATED WITH DOWN SYN-DROME IN A MOUSE MODEL
poster abstractTrisomy 21 is the genetic source of the group of phenotypes commonly known as Down syndrome (DS). These phenotypes include cognitive im-pairment, heart defects and craniofacial abnormalities, including a small mandible. The Ts65Dn mouse model contains three copies of approximately half the genes found on human chromosome 21 and exhibits similar pheno-types to individuals with DS including a small, dysmorphic mandible. Our lab has traced this deficit to a smaller first branchial arch (BA1) consisting of fewer neural crest cells (NCCs) at embryonic day 9.5 (E9.5). At E9.5, Dyrk1a, a gene known to affect craniofacial development, is upregulated in the BA1, likely contributing to its cell deficit. Using epigallocatechin gallate (EGCG), an extract from green tea and a known inhibitor of Dyrk1a, we are attempting to rescue this deficit. We hypothesize the consumption of EGCG by pregnant mothers at E7 and E8 will rescue the mandibular deficit in de-veloping embryos by reducing the expression or activity of Dyrk1a. From our data we conclude the treatment of pregnant mothers with EGCG results in increased embryo size of trisomic embryos. Further analysis will be done to determine embryo volume, the volume of the BA1, and number of NCCs within the BA1 to determine the effects of EGCG in vivo. This research will better our understanding of craniofacial development and could lead to po-tential genetic-based therapies in the future
An overview of the history and work of Liverpool Public Health Observatory, and its impact on policy and services
Liverpool Public Health Observatory (LPHO) was established in 1990 to provide intelligence to Merseyside Health Authorities (later Primary Care Trusts and now Local Authority Public Health Departments). The work programme for LPHO is now managed by the Cheshire and Merseyside Public Health Intelligence Network, on behalf of the Directors of Public Health. The Intelligence Network identify areas of work based on local priorities and those of the CHAMPS public health collaborative service1. A project lead, usually a member of local authority staff, is identified, and a working group is established – the working group provides expert input into the projects, and a steer to researchers in the University regarding scope and local requirements. Academic support for the projects is provided by the University of Liverpool. When reports are complete, they are uploaded to LPHO’s website, and disseminated widely via CHAMPS to relevant professionals, including relevant leads within the NHS and local authorities, and presented at relevant local, national and international conferences and events. Projects are now evaluated six months after they have been completed. This overview report provides a summary of some of the more recent reports that have been compiled by LPHO, including evaluation findings where these are available, and the impact that LPHO’s work has had on public health practice. An appendix which lists all LPHO’s publications is included at the end of this report for future reference
- …
