Papers by Christopher Haines
Monthly Notices of the Royal Astronomical Society, 2010
We analyse Spitzer Multiband Imaging Photometer (MIPS) 24-μm observations, and Sloan Digital Sky ... more We analyse Spitzer Multiband Imaging Photometer (MIPS) 24-μm observations, and Sloan Digital Sky Survey Data Release 7 optical broad-band photometry and spectra, to investigate the star formation (SF) properties of galaxies residing in the Coma supercluster region. We find that SF in dwarf galaxies is quenched only in the high-density environment at the centre of clusters and groups, but that passively evolving massive galaxies are found in all environments, indicating that massive galaxies can become passive via internal processes. The SF-density relation observed for the massive galaxies is weaker relative to the dwarfs, but both show a trend for the fraction of star-forming galaxies (f SF) declining to ∼0 in the cluster cores. We find that active galactic nucleus activity is also suppressed among massive galaxies residing in the cluster cores. We present evidence for a strong dependence of the mechanism(s) responsible for quenching SF in dwarf galaxies on the cluster potential, resulting in two distinct evolutionary pathways. First, we find a significant increase (at the 3σ level) in the mean equivalent width of Hα emission among star-forming dwarf galaxies in the infall regions of the Coma cluster and the core of Abell 1367 with respect to the overall supercluster population, indicative of the infalling dwarf galaxies undergoing a starburst phase. We identify these starburst galaxies as the precursors of the post-starburst k + A galaxies. Extending the survey of k + A galaxies over the whole supercluster region, we find 11.4 per cent of all dwarf (z mag >15) galaxies in the Coma cluster and 4.8 per cent in the Abell 1367 have post-starburst like spectra, while this fraction is just 2.1 per cent when averaged over the entire supercluster region (excluding the clusters). This points to a cluster-specific evolutionary process in which infalling dwarf galaxies undergo a starburst and subsequent rapid quenching due to their passage through the dense intracluster medium. In galaxy groups, the SF in infalling dwarf galaxies is instead slowly quenched due to the reduced efficiency of ram-pressure stripping. We show that in the central ∼2 h −1 70 Mpc of the Coma cluster, the (24 − z) near-infrared/midinfrared (MIR) colour of galaxies is correlated with their optical (g − r) colour and Hα emission, separating all MIR-detected galaxies into two distinct classes of 'red' and 'blue'. By analysing the spatial and velocity distribution of galaxies detected at 24 μm in Coma, we find that the (optically) red 24-μm detected galaxies follow the general distribution of 'all' the spectroscopic members, but their (optically) blue counterparts (i) are almost completely absent in the central ∼0.5 h −1 70 Mpc of Coma and (ii) have a remarkable peak in their velocity distribution, corresponding to the mean radial velocity of the galaxy group NGC 4839, suggesting that a significant fraction of the 'blue' MIR galaxies are currently on their first infall towards the cluster. The implications of adopting different SF-rate tracers for quantifying evolutionary trends like the Butcher-Oemler effect are also discussed.
MedEdPORTAL Publications, 2010
Abstract This resource is designed as a simulation exercise. It is one of a series of exercises u... more Abstract This resource is designed as a simulation exercise. It is one of a series of exercises utilized for education and training about pediatric emergencies for residents, nurses, and prehospita...
The study presented in this article takes a closer look at how French and German highschool stude... more The study presented in this article takes a closer look at how French and German highschool students deal with a mathematical modeling problem, what blockages they encounter and how differences in the modeling processes between students from both nations can be explained by differences between the teaching and learning of mathematical modeling in France and Germany. To better understand these differences, firstly, a brief overview is provided on the historical development of mathematics education in both countries, with a focus on mathematical modeling, followed by a qualitative empirical study in both France and Germany. Two main differences can be identified: students' handling of the real-world situation and their striving for accuracy. Possible reasons for these differences are discussed in relation to national teaching traditions.
Ultrasound in Medicine & Biology, 2009
Teaching Mathematics and its Applications, 2005
ABSTRACT
Teaching Mathematics and its Applications, 1992
Solar Energy Materials and Solar Cells, 2012
The effect of dye concentration on the efficiency of a luminescent concentrator based on a peryle... more The effect of dye concentration on the efficiency of a luminescent concentrator based on a perylene diimide (PDI) derivative incorporated in poly(methyl methacrylate) films cast on glass substrates is described. The predictions of ray-trace modelling are compared to experimental data from integrating sphere luminescence measurements. Increasing the PDI concentration leads to aggregation of the dye and an associated shift in the emission spectrum. The larger Stokes shift between emission and absorption spectra of the aggregated form reduces luminescence re-absorption and increases collection efficiency. However, the lower fluorescence quantum yield of the PDI aggregates restricts overall absorbed light to luminescence conversion. The relevance of the results to optimize organic molecule based luminescent solar concentrators is discussed.
Quality in Higher Education, 1999
The article reports on a small-scale project that investigated the potential of using a benchmark... more The article reports on a small-scale project that investigated the potential of using a benchmarking club on assessment practices in History as a means of establishing and comparing academic standards. The context of the project is described and the benchmarking club's key ...
Primary Care: Clinics in Office Practice, 2006
Coronary heart disease (CHD) is the leading cause of death for both men and women of all races an... more Coronary heart disease (CHD) is the leading cause of death for both men and women of all races and all ethnicities in the United Status. Twenty percent of all Americans and one third of all American men die from CHD [1]. Cholesterol is a major modifiable risk factor for CHD, and multiple studies have demonstrated that lowering cholesterol improves CHD risk [2]. This finding has important public health implications and emphasizes the need for primary care clinicians to become experts in diagnosing and managing dyslipidemia. Epidemiology According to National Health and Nutrition Examination Survey III (NHANES III) data, 26 percent of American adults have dyslipidemia [3]. The prevalence of dyslipidemia varies with the population being studied, with highest incidence in patients with premature CHD, ranging from 75% to 85% [4]. There is also a strong familial tendency toward dyslipidemia, such that 70% of patients with a lipid abnormality have a family history of dyslipidemia. Among men, the prevalence of dyslipidemia increases with age, peaking at 40% in men aged 65 to 74. Prevalence among men also increases with weight, increasing from 31% to 36% to 44% as weight goes from normal to overweight to obese. With the release of the 2001 Adult Treatment Panel (ATP) III guidelines, the overall eligibility for treatment of men has increased by 157% [5]. Despite such high numbers, screening and treatment of dyslipidemia in men remain low. In one survey from 2000, only 63%
Monthly Notices of the Royal Astronomical Society, 2009
We present the first galaxy evolution results from the Local Cluster Substructure Survey (Lo-CuSS... more We present the first galaxy evolution results from the Local Cluster Substructure Survey (Lo-CuSS), a multi-wavelength survey of 100 X-ray selected galaxy clusters at 0.15 z 0.3. Lo-CuSS combines far-UV through far-IR observations of cluster galaxies with gravitational lensing analysis and X-ray data to investigate the interplay between the hierarchical assembly of clusters and the evolution of cluster galaxies. Here we present new panoramic Spitzer/MIPS 24µm observations of the merging cluster Abell 1758 at z=0.279 spanning 6.5×6.5 Mpc and reaching a 90% completeness limit of S 24µm =400µJy. We estimate a global cluster star-formation rate of SFR 24µm =910±320 M ⊙ yr −1 within R<3 Mpc of the cluster centre, originating from 42 galaxies with L 8−1000µm >5×10 10 L ⊙. The obscured activity in A 1758 is therefore comparable with that in Cl 0024+1654, the most active cluster previously studied at 24µm. The obscured galaxies faithfully trace the cluster potential as revealed by the weak-lensing mass map of the cluster, including numerous mass peaks at R∼2-3 Mpcthat are likely associated with infalling galaxy groups and filamentary structures. However the core (R ∼ <500 kpc) of A 1758N is ∼2× more active in the infrared than that of A 1758S, likely reflecting differences in the recent dynamical history of the two clusters. The 24µm results from A 1758 therefore suggest that dust-obscured cluster galaxies are common in merging clusters and suggests that obscured activity in clusters is triggered by both the details of cluster-cluster mergers and processes that operate at larger radii including those within in-falling groups. Our ongoing far-UV through far-IR observations of a large sample of clusters should allow us to disentangle the different physical processes responsible for triggering obscured star formation in clusters.
Letters in Mathematical Physics, 1979
Journal of the American Medical Directors Association, 2005
To determine if an educational program can improve knowledge and attitude among ancillary staff o... more To determine if an educational program can improve knowledge and attitude among ancillary staff on end-of-life care issues in a long-term care facility. A pilot study using a pre- and post-test design prior to and at the completion of an education intervention. A long-term care facility in suburban Philadelphia that has 150 assisted living beds and 53 nursing home beds. Long-term care ancillary staff including certified nursing assistants (called &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;care managers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; at this facility), social workers, recreational therapists, and food service workers. The intervention was a novel educational program consisting of five in-service lectures with accompanying take home self-study modules for ancillary staff in long-term care entitled &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;Dignity in Dementia.&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; Ancillary staff attitudes and knowledge on end-of-life issues in dementia were assessed with a knowledge and attitude questionnaire pre- and post-intervention. One-year follow-up questionnaires were administered to assess long-term maintenance of knowledge and attitude changes. Thirty-two ancillary staff completed the pre-intervention questionnaires. Twenty-nine ancillary staff completed the post-intervention questionnaires (90.6%). There was a significant change in the end-of-life knowledge level of the ancillary staff (P =.0270). Specifically, there was a significant change in one question dealing with dementia as a terminal disease (P = .006). There were also significant changes in the average attitude scores of the ancillary staff. (P = .0242). One-year follow-up revealed that both knowledge and attitude changes were maintained. This pilot project demonstrates that a staff educational program on end-of-life care for dementia residents can improve end-of-life knowledge and attitudes among long-term care ancillary staff and that this improvement can be maintained for up to 1 year. This intervention is easily reproducible in the long-term care setting. This project is an important step in helping improve end-of-life care for dementia residents in long-term care settings by improving the knowledge and attitudes of their caregivers.
International Journal of Mathematical Education in Science and Technology, 2004
... the context and situation in which the mathematical modelling task is embedded, student and t... more ... the context and situation in which the mathematical modelling task is embedded, student and teacher ... the language of the Maori does not readily lend itself to mathematical concepts developed for ... knowledge base appears to take an extended time to develop and needs a basis ...
International Journal of Mathematical Education in Science and Technology, 2001
As part of a broader research objective concerned with identifying the range of employer defined ... more As part of a broader research objective concerned with identifying the range of employer defined skill profiles that characterize workplace performance, this paper examines skill contexts for Application of Number, one of six UK defined Key Skills similar to Australian defined Key Competencies. Following the construction of questionnaires, grounded in the Analytic Hierarchy Process, applications of the instrument in both the UK and in Australia produced a ratio scale of priorities within the Key Skills area. This enabled a specification of the relative balance between classical competencies, e.g. facility with pen and paper calculations and emerging competencies demanded by the effective use of ICT. Relevance to workplace learning, including the transition from school to employment, and related aspects of mathematics education are discussed. Among the research outcomes is that spreadsheets are assuming a pre-eminent position and that this is an overriding priority for each defined activity and at each job level.
Brain Research, 2003
Improvements in both obstetric and paediatric care have been responsible for a continuing reducti... more Improvements in both obstetric and paediatric care have been responsible for a continuing reduction in mortality in extremely premature infants. However, higher survival rates have been at the expense of more long-term neurological damage. Various animal models have been developed to study the effect of hypoxic-ischemic insults on the brain. However, established models like the postnatal day 7 rat model represent damage found in term infants rather than in preterm infants of 24-28 weeks' gestation, and produce a severe form of injury resulting in high mortality rates. In this study we developed a reliable model of minor hypoxic-ischemic brain injury in postnatal day 3 rats. At this maturity, the pattern of damage represents that expected in a preterm infant suffering a non-lethal perinatal insult. We found that minor changes in duration of insult and both temperature and humidity produced wide fluctuations in the degree of injury observed. By maintaining strict control over experimental conditions including duration of insult, temperature and humidity, we produced a reliable model of minor injury primarily affecting all five areas of the cerebral cortex, and also the thalamus (area 7) and basal ganglia (area 8). Differences were significant compared to normal controls and sham-operated animals (p < 0.05). These areas represent the primary motor, insular, visual and temporal cortices. The overall mortality rate in this study was 12.3%.
Astronomy and Astrophysics, 2007
Context. Weak lensing applied to deep optical images of clusters of galaxies provides a powerful ... more Context. Weak lensing applied to deep optical images of clusters of galaxies provides a powerful tool to reconstruct the distribution of the gravitating mass associated to these structures. Aims. We use the shear signal extracted by an analysis of deep exposures of a region centered around the galaxy cluster ABCG 209, at redshift z ∼ 0.2, to derive both a map of the projected mass distribution and an estimate of the total mass within a characteristic radius. Methods. We use a series of deep archival R-band images from CFHT-12k, covering an area of ∼ 0.3 deg 2. We determine the shear of background galaxy images using a new implementation of the modified Kaiser-Squires-Broadhurst KSB+ pipeline for shear determination, which we has been tested against the "Shear TEsting Program 1 and 2" simulations. We use mass aperture statistics to produce maps of the 2 dimensional density distribution, and parametric fits using both Navarro-Frenk-White and singular-isothermal-sphere profiles to constrain the total mass. Results. The projected mass distribution shows a pronounced asymmetry, with an elongated structure extending from the SE to the NW. This is in general agreement with the optical distribution previously found by other authors. A similar elongation was previously detected in the X-ray emission map, and in the distribution of galaxy colours. The circular NFW mass profile fit gives a total mass of M200 = 7.7 +4.3 −2.7 10 14 M⊙ inside the virial radius r200 = 1.8 ± 0.3 Mpc. Conclusions. The weak lensing profile reinforces the evidence for an elongated structure of ABCG 209, as previously suggested by studies of the galaxy distribution and velocities.
Journal of Assisted Reproduction and Genetics, 2005
To evaluate the responses of cultured oviduct mucosal cells to exogenous estradiol treatment in r... more To evaluate the responses of cultured oviduct mucosal cells to exogenous estradiol treatment in regulating the mRNA expression of vascular endothelial growth factor (VEGF) and its receptors. The mucosal layer of the ampullary regions of the human oviduct was isolated and cultured with (study groups) or without (control group) the addition of exogenous estradiol in five different concentrations. Semiquantitative reverse-transcriptase-polymerase chain reaction was performed on the oviduct mucosal cells before and after the 6-day culture. There were no significant differences in the mRNA expression of VEGF and its receptors, both KDR and flt-1, between the five study groups and the control group. The mRNA expression of VEGF and its receptors is not altered by exogenous estradiol treatment in cultured oviduct. This helps to explain the mechanism of temporal regulation of VEGF in human oviduct, which reaches the peak level in the peri-ovulatory stage when both the serum estradiol and gonadotropins concentrations are high.
Journal of Assisted Reproduction and Genetics, 2006
To examine changes in the ratio of Bax and Bcl-2 mRNA expression throughout the ovulatory cycle i... more To examine changes in the ratio of Bax and Bcl-2 mRNA expression throughout the ovulatory cycle in the ampullary region of the human oviduct. The mucosal layer was isolated from the human oviduct tissue and semiquantitative reverse-transcriptase polymerase chain-reaction (RT-PCR) analysis of mRNA of Bax and Bcl-2 was performed. Immunohistochemistry provided the cellular localization of the Bax and Bcl-2 proteins. The ratio of expression of Bax and Bcl-2 mRNA was examined in the ampullary region of the oviduct in samples obtained in the follicular, periovulatory, and luteal phases of the ovulatory cycle. Bax expression was constant in the follicular and periovulatory phase but showed a significant increase in the luteal phase. The Bax protein was present in all oviduct mucosal epithelial cells and the intensity of staining increased in luteal phase samples. Bcl-2 was expressed at a relatively constant level throughout the ovulatory cycle. The Bcl-2 protein was present in some but not all mucosal epithelial cells and the proportion of positive cells remained constant throughout the ovulatory cycle. The proapoptotic gene Bax shows a significant increase in mRNA expression in the luteal phase of the ovulatory cycle while the expression level of the antiapoptotic gene Bcl-2 remains constant throughout the ovulatory cycle. The ratio of Bax:Bcl-2 increases significantly in the luteal phase consistent with cells undergoing apoptosis.
Journal of Assisted Reproduction and Genetics, 2005
The ratio of the active progesterone receptor B isoform is higher in the ampullary region of the ... more The ratio of the active progesterone receptor B isoform is higher in the ampullary region of the oviduct. To examine mRNA expression of progesterone receptor isoforms AB and B in oviduct mucosal tissue during the ovulatory cycle and in the different functional regions of the human oviduct. The mucosal layer was isolated from human oviduct tissue and semi-quantitative RT-PCR for progesterone isoforms AB and B was performed. The RT-PCR results were verified by immunohistochemistry. The isthmic region showed no mRNA expression of either progesterone receptor isoform while the relative ratio of the B isoform was significantly higher in the ampullary region compared to the fimbrial region. There was a significant increase in the ratio of PRB to PRAB in the ampullary region compared to the fimbrial region in all samples. We found an increase in the relative abundance of the progesterone receptor B isoform in the ampullary region which is the site of fertilization and early embryo cleavage. Our results indicate that progesterone responsive genes are more likely to be activated in the ampullary region of the oviduct due to the difference in PRAB to PRB ratio. Providing support for the hypothesis that progesterone may play a specific role in providing an appropriate environment for sperm capacitation, fertilization and early embryo cleavage.
Journal of Assisted Reproduction and Genetics, 2004
Purpose : To investigate whether commonly used test tube warming devices maintain a constant temp... more Purpose : To investigate whether commonly used test tube warming devices maintain a constant temperature in follicular fluid aspirates. Methods : By using a digital thermocouple, temperature was measured and comparisons were made between an analog dry block heater, a digital dry block heater, and a thermostatic test tube heater. Results : For small fluid volumes, temperature in the block heaters increased above 37 • C after being in the block for over 2 min. The thermostatic heater maintained a constant temperature, but this was below the factory setting of 36.9 • C. Temperature maintenance was influenced by fluid volume in each tube. Conclusions : One of the key factors in the handling of gametes and embryos is the maintenance of constant temperature. Test tube warming devices require verification of their ability to maintain fluid at the desired temperature. Temperature may vary with fluid volume and the type of test tube warming device used.
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Papers by Christopher Haines