Constraints on the Growth and Spin of the Supermassive Black Hole in M32 From High Cadence Visible Light Observations

We present 1-second cadence observations of M32 (NGC221) with the CHIMERA instrument at the Hale 200-inch telescope of the Palomar Observatory. Using field stars as a baseline for relative photometry, we are able to construct a light curve of the nucleus in the g-prime and r-prime band with 1sigma=36 milli-mag photometric stability. We derive a temporal power spectrum for the nucleus and find no evidence for a time-variable signal above the noise as would be expected if the nuclear black hole were accreting gas. Thus, we are unable to constrain the spin of the black hole although future work will use this powerful instrument to target more actively accreting black holes. Given the black hole mass of (2.5+/-0.5)*10^6 Msun inferred from stellar kinematics, the absence of a contribution from a nuclear time-variable signal places an upper limit on the accretion rate which is 4.6*10^{-8} of the Eddington rate, a factor of two more stringent than past upper limits from HST. The low mass of the black hole despite the high stellar density suggests that the gas liberated by stellar interactions was primarily at early cosmic times when the low-mass black hole had a small Eddington luminosity. This is at least partly driven by a top-heavy stellar initial mass function at early cosmic times which is an efficient producer of stellar mass black holes. The implication is that supermassive black holes likely arise from seeds formed through the coalescence of 3-100 Msun mass black holes that then accrete gas produced through stellar interaction processes.Comment: 8 pages, 3 figures, submitted to the Astrophysical Journal, comments welcom

Key dating features for timber-framed dwellings in Surrey

This article is made available through the Brunel Open Access Publishing Fund. Copyright @ The Vernacular Architecture Group 2013. MORE OpenChoice articles are open access and distributed under the terms of the Creative Commons Attribution License 3.0.The main component of the Surrey Dendrochronology Project is the accurate dating of 177 ‘dwellings’, nearly all by tree-ring analysis. The dates are used to establish date ranges for 52 ‘key features’, which cover many aspects of timber-framing from building type to details of carpentry. It is shown that changes of method and fashion were in many cases surprisingly rapid, almost abrupt in historical terms. Previous dating criteria for timber-framed dwellings in the county have been refined and new criteria introduced. Clusters of change from the 1440s and the 1540s are shown and some possible historical links suggested.The Heritage Lottery Fund, the Domestic Buildings Research Group (Surrey), the Surrey Archaeological Society and the historical societies of Charlwood, Farnham and Nutfield

Does angiotensin-1 converting enzyme genotype influence motor or cognitive development after pre-term birth?

BACKGROUND: Raised activity of the renin-angiotensin system (RAS) may both amplify inflammatory and free radical responses and decrease tissue metabolic efficiency and thus enhance cerebral injury in the preterm infant. The angiotensin-converting enzyme (ACE) DD genotype is associated with raised ACE and RAS activity as well as potentially adverse stimuli such as inflammation. The DD genotype has been associated with neurological impairments in the elderly, and thus may be also associated with poorer motor or cognitive development amongst children born preterm prematurely. METHODS: The association of DD genotype with developmental progress amongst 176 Caucasian children born at less than 33 weeks gestation (median birthweight 1475 g, range 645–2480 g; gestation 30 weeks, range 22–32; 108 male) was examined at 2 and 5 1/2 years of age. Measured neuro-cognitive outcomes were cranial ultrasound abnormalities, cerebral palsy, disability, Griffiths Developmental Quotient [DQ] at 2 yrs, and General Cognitive Ability [British Ability Scales-11] and motor performance [ABC Movement], both performed at 5 1/2 yrs. All outcomes were correlated with ACE genotype. RESULTS: The DD genotype was not associated with lower developmental quotients even after accounting for important social variables. CONCLUSION: These data do not support either a role for ACE in the development of cognitive or motor function in surviving infants born preterm or inhibition of ACE as a neuroprotective therapy

Becoming the leader: Leadership as material presence

This paper seeks to understand leaders as material presences. Leadership theory has traditionally explored leaders as sites of disembodied traits, characteristics and abilities. Our qualitative, mixed method study suggests that managers charged with the tasks of leadership operate within a very different understanding. Their endogenous or lay theory understands leadership as physical, corporeal and visible, and as something made manifest through leaders’ material presence. This theory-in-practice holds that leadership qualities are signified by the leader’s physical appearance: the good leader must look the part. Actors consequently work on their own appearance to present an image of themselves as leader. They thus offer a fundamental challenge to dominant exogenous, or academic, theories of leadership. To understand the unspoken assumptions that underpin the lay theory of leadership as material presence, we interrogate it using the new materialist theory of Karen Barad and the object relations theory of Christopher Bollas. This illuminates the lay theory’s complexities and sophisticated insights. In academic terms it offers a theory of how sentient and non-sentient actors intra-act and performatively constitute leadership through complex entanglements that enact and circulate organizational and leadership norms. The paper’s contribution is thus a theory of leadership micro-dynamics in which the leader is materialized through practices of working on a corporeal self for presentation to both self and others

Conservation status of New Zealand freshwater invertebrates, 2013

The conservation status of 644 freshwater invertebrate taxa, across five Phyla, 28 Orders and 75 Families, was assessed using the New Zealand Threat Classification System (NZTCS) criteria. Forty-six species were ranked Nationally Critical, 11 Nationally Endangered and 16 Nationally Vulnerable. One hundred and seventy-two taxa were listed as Data Deficient. A full list is presented, along with summaries and brief notes on the most important changes. This list replaces all previous NZTCS lists for freshwater invertebrates

Process modelling of linear friction welding (LFW) between AA2124/SICp composite and unreinforced alloy

In the present study, the Linear Friction Welding (LFW) process between a bar of Metal Matrix Composite (MMC) AMC225xe (AA2124 with 25% SiC particulate reinforcement) and a bar of unreinforced base alloy was simulated using the commercial finite element package ABAQUSTM. Fully coupled implicit thermo-mechanical analysis procedure was employed, with semi-automatic re-meshing using Python scripting and output database scripting methods for extracting deformed configurations. Due to the large deformation near the weld region, multiple analyses were carried out between each re-meshing stage in order to limit the element distortion. Comparison of the simulation results with the experimental data collected during welding, and with post-weld optical section micrograph has shown satisfactory agreement

Using psychological and physiological measures in arts-based activities in a community sample of people with a dementia and their caregivers: a feasibility and pilot study

Introduction: Nearly all community-based dementia care studies employ either qualitative methods or use a combination of self-report questionnaire within mixed-methods research designs. Physiological measures, however, are rarely used in community-based studies with this population yet could provide valuable biological information for specific activities across the course of the dementias. Method: The study employed a within-subjects design to assess the feasibility of obtaining physiological measures (salivary cortisol and Heart Rate Variability (HRV)) alongside subjective measures of wellbeing and stress using Visual Analogue Scales (VAS) during two community-based activiti of choral singing and art viewing, respectively, for People With Dementia (PWD) in the early to middle stages of impairment and their caregivers. Results: As anticipated, pre-post subjective wellbeing measures were relatively easy to complete by PWD and caregivers with no substantive difficulties observed or reported; significant increases in composite wellbeing, happiness and optimism were found. Continuous measurement of physiological data of HRV through a sensor-based device (Empatica® E4) was also found to be neither non-intrusive to participants nor disruptive to the interventions. Preliminary indications showed, for example, HRV significantly increased for PWD during choral singing, which may be associated with an increase in wellbeing. Measuring stress hormones through pre-post saliva samples, however, encountered several difficulties. Conclusions: The findings provide support for the feasibility of using non-intrusive sensor-based physiological measures alongside subjective measures for this population. Subjective measures may also give more confidence in interpreting directionality of physiological measures. A full pilot study is warranted to further investigate interactions of physiological and psychological variables in choral singing and viewing art activities but it is uncertain whether measuring stress hormones through saliva collection is feasible for this population and raised doubts about their use in a large scale trial. Holding particular promise is the use of sensor-based technology across different stages of dementia as well as across different activities

Image analysis applied to Brillouin images of tissue-mimicking collagen gelatins

This is the final version. Available on open access from Optical Society of America via the DOI in this recordBrillouin spectroscopy is an emerging analytical tool in biomedical and biophysical sciences. It probes viscoelasticity through the propagation of thermally induced acoustic waves at gigahertz frequencies. Brillouin light scattering (BLS) measurements have traditionally been performed using multipass Fabry-Pérot interferometers, which have high contrast and resolution, however as they are scanning spectrometers they often require long acquisition times at low laser powers. In the last decade, a new concept of Brillouin spectrometer has emerged, making use of highly angle-dispersive Virtually Imaged Phase Array (VIPA) etalons, which enable fast acquisition times for minimally turbid materials, when high contrast is not imperative. The ability to acquire Brillouin spectra rapidly, together with long term system stability, make this system a viable candidate for use in biomedical applications, especially to probe live cells and tissues. While various methods are being developed to improve system contrast and speed, little work has been published discussing the details of imaging data analysis and spectral processing. Here we present a method that we developed for the automated retrieval of Brillouin line shape parameters from imaging datasets acquired with a dual-stage VIPA Brillouin microscope. We applied this method for the first time to BLS measurements of collagen gelatin hydrogels at different hydration levels and cross-linker concentrations. This work demonstrates that it is possible to obtain the relevant information from Brillouin spectra using software for real-time high-accuracy analysis.Engineering and Physical Sciences Research Council (EPSRC)Cancer Research U