16,506 research outputs found
The discolouration of human teeth from archaeological contexts: Elemental analysis of a black tooth from a Roman cranium recovered from the River Witham, Lincoln, UK.
A human cranium was recovered from the River Witham, Lincoln, UK, at Stamp End Lock during a police operation in 2002. Although extensive trauma was noted, the skull was not of forensic interest since radiocarbon dating revealed that the individual had lived during the Roman occupation of Lincoln, almost 2,000 years ago. The skull had unusual black “metallic” staining on the occlusal surfaces of the teeth. As this kind of staining is relatively uncommon, it was investigated to determine the possible cause. An individual tooth was subjected to two elemental analyses: inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX). A small sample of modern teeth was also analysed for comparison to determine “normal” ranges of certain elements. Analysis of the ancient tooth shows very high levels of manganese (275 µg/g) and iron (1540 µg/g) compared to modern teeth values (1.90 µg/g Mn and 40.81 µg/g Fe). These results were consistent with the black staining arising from iron and manganese infiltrating bone and dental tissue from the depositional environment, and not a consequence of diet, pathological process or cultural practices
Improvements in prevalence trend fitting and incidence estimation in EPP 2013
OBJECTIVE: Describe modifications to the latest version of the Joint United Nations Programme on AIDS (UNAIDS) Estimation and Projection Package component of Spectrum (EPP 2013) to improve prevalence fitting and incidence trend estimation in national epidemics and global estimates of HIV burden. METHODS: Key changes made under the guidance of the UNAIDS Reference Group on Estimates, Modelling and Projections include: availability of a range of incidence calculation models and guidance for selecting a model; a shift to reporting the Bayesian median instead of the maximum likelihood estimate; procedures for comparison and validation against reported HIV and AIDS data; incorporation of national surveys as an integral part of the fitting and calibration procedure, allowing survey trends to inform the fit; improved antenatal clinic calibration procedures in countries without surveys; adjustment of national antiretroviral therapy reports used in the fitting to include only those aged 15–49 years; better estimates of mortality among people who inject drugs; and enhancements to speed fitting. RESULTS: The revised models in EPP 2013 allow closer fits to observed prevalence trend data and reflect improving understanding of HIV epidemics and associated data. CONCLUSION: Spectrum and EPP continue to adapt to make better use of the existing data sources, incorporate new sources of information in their fitting and validation procedures, and correct for quantifiable biases in inputs as they are identified and understood. These adaptations provide countries with better calibrated estimates of incidence and prevalence, which increase epidemic understanding and provide a solid base for program and policy planning
The intersection of pop culture and non-traditional sports: An examination of the niche market of quidditch
The real sport of quidditch was recently adapted from the fictional sport of the same namesake in the Harry Potter (HP) franchise. Quidditch is played at hundreds of locations across the USA and around the world. Considering the lack of marketing research on non-traditional, co-ed sports and the innovative nature of quidditch, the purpose of this research was to conduct a qualitative, grounded theory study (Strauss and Corbin, 1990) on the athletes and determine how involvement and identification is associated with these individuals becoming a viable niche market within the sports industry. Five factors led towards a desire to partake in quidditch and become involved and identified with the sport: identification with Harry Potter, camaraderie and friendship, desire to have fun, desire to try something new, and desire to get in shape. Copyright © 2012 Inderscience Enterprises Ltd
Gravitational energy of a magnetized Schwarzschild black hole - a teleparallel approach
We investigate the distribution of gravitational energy on the spacetime of a
Schwarzschild black hole immersed in a cosmic magnetic field. This is done in
the context of the {\it Teleparallel Equivalent of General Relativity}, which
is an alternative geometrical formulation of General Relativity, where gravity
is describe by a spacetime endowed with torsion, rather than curvature, with
the fundamental field variables being tetrads. We calculate the energy enclosed
by a two-surface of constant radius - in particular, the energy enclosed by the
event horizon of the black hole. In this case we find that the magnetic field
has the effect of increasing the gravitational energy as compared to the vacuum
Schwarzschild case. We also compute the energy (i) in the weak magnetic field
limit, (ii) in the limit of vanishing magnetic field, and (iii) in the absence
of the black hole. In all cases our results are consistent with what should be
expected on physical grounds.Comment: version to match the one to be published on General Relativity and
Gravitatio
When do words hurt? A multiprocess view of the effects of verbalization on visual memory
Verbal overshadowing reflects the impairment in memory performance following verbalization of nonverbal stimuli. However, it is not clear whether the same mechanisms are responsible for verbal overshadowing effects observed with different stimuli and task demands. In the present article, we propose a multiprocess view that reconciles the main theoretical explanations of verbal overshadowing deriving from the use of different paradigms. Within a single paradigm, we manipulated both the nature of verbalization at encoding (nameability of the stimuli) and postencoding (verbal descriptions), as well as the nature (image transformation or recognition) and, by implication, the demands of the final memory task (global or featural). Results from 3 experiments replicated the negative effects of encoding and postencoding verbalization in imagery and recognition tasks, respectively. However, they also showed that the demands of the final memory task can modulate or even reverse verbal overshadowing effects due to both postencoding verbalization and naming during encoding
Guilt, shame and expressed emotion in carers of people with long-term mental health difficulties: A systematic review
Long-term survival rates of laryngeal cancer patients treated by radiation and surgery, radiation alone, and surgery alone : studied by lognormal and Kaplan-Meier survival methods
BACKGROUND: Validation of the use of the lognormal model for predicting long-term survival rates using short-term follow-up data. METHODS: 907 cases of laryngeal cancer were treated from 1973–1977 by radiation and surgery (248), radiation alone (345), and surgery alone (314), in registries of Connecticut and Metropolitan Detroit of the SEER database, with known survival status up to 1999. Phase 1 of this study used the minimum chi-square test to assess the goodness of fit of the survival times of those who died with disease to a lognormal distribution. Phase 2 used the maximum likelihood method to estimate long-term survival rates using short-term follow-up data. In order to validate the lognormal model, the estimated long-term cancer-specific survival rates (CSSR) were compared with the values calculated by the Kaplan-Meier (KM) method using long-term data. RESULTS: The 25-year CSSR were predicted to be 72%, 68% and 65% for treatments by radiation and surgery, by radiation alone, and by surgery alone respectively, using short-term follow-up data by the lognormal model. Corresponding results calculated by the KM method were: 72+/-3%, 68+/-3% and 66+/-4% respectively. CONCLUSIONS: The lognormal model was validated for the prediction of the long-term survival rates of laryngeal cancer patients treated by these different methods. The lognormal model may become a useful tool in research on outcomes
Engaging residents in regeneration: Lessons from Pendleton
A wide-ranging urban regeneration programme is taking place in the Pendleton area of Salford. A substantial element of this work entails the refurbishment and retrofit of existing, tenanted properties. Flats and houses have been subject to kitchen and bathroom replacements, new windows and doors, and a new heating system based around an air source heat pump, and these modifications are being rolled out across the area. Throughout this process, effective tenant engagement is essential. Such refurbishment has the potential to be disruptive and stressful for residents; however, appropriate information and channels of communication can help to mitigate this. It is important that residents are well-informed and also have an active voice in the process of refurbishment and its outcome.
The Together Housing Group have been awarded the Customer Service Excellence mark, which places an emphasis developing customer insight and the robust management of customer satisfaction. The organisation have commissioned the Sustainable Housing & Urban Studies Unit to carry out a rapid review of handover and tenant engagement with respect to the refurbishment works carried out to date. The study is a review, based on desk research, discussions with relevant Pendleton Together and Keepmoat staff, and interviews with contractors and tenants occupying a range of properties. In total 30 interviews were conducted
Black Branes in a Box: Hydrodynamics, Stability, and Criticality
We study the effective hydrodynamics of neutral black branes enclosed in a
finite cylindrical cavity with Dirichlet boundary conditions. We focus on how
the Gregory-Laflamme instability changes as we vary the cavity radius R. Fixing
the metric at the cavity wall increases the rigidity of the black brane by
hindering gradients of the redshift on the wall. In the effective fluid, this
is reflected in the growth of the squared speed of sound. As a consequence,
when the cavity is smaller than a critical radius the black brane becomes
dynamically stable. The correlation with the change in thermodynamic stability
is transparent in our approach. We compute the bulk and shear viscosities of
the black brane and find that they do not run with R. We find mean-field theory
critical exponents near the critical point.Comment: 23 pages, 3 figures. v2: added comments on first-order phase
transitio
Goodness-of-fit tests for neural population models: the multivariate time-rescaling theorem
Poster Presentation from Nineteenth Annual Computational Neuroscience Meeting: CNS*2010 San Antonio, TX, USA. 24-30 July 2010 Statistical models of neural activity are at the core of the field of modern computational neuroscience. The activity of single neurons has been modeled to successfully explain dependencies of neural dynamics to its own spiking history, to external stimuli or other covariates [1]. Recently, there has been a growing interest in modeling spiking activity of a population of simultaneously recorded neurons to study the effects of correlations and functional connectivity on neural information processing (existing models include generalized linear models [2,3] or maximum-entropy approaches [4]). For point-process-based models of single neurons, the time-rescaling theorem has proven to be a useful toolbox to assess goodness-of-fit. In its univariate form, the time-rescaling theorem states that if the conditional intensity function of a point process is known, then its inter-spike intervals can be transformed or “rescaled” so that they are independent and exponentially distributed [5]. However, the theorem in its original form lacks sensitivity to detect even strong dependencies between neurons. Here, we present how the theorem can be extended to be applied to neural population models and we provide a step-by-step procedure to perform the statistical tests. We then apply both the univariate and multivariate tests to simplified toy models, but also to more complicated many-neuron models and to neuronal populations recorded in V1 of awake monkey during natural scenes stimulation. We demonstrate that important features of the population activity can only be detected using the multivariate extension of the test. ..
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