253 research outputs found
From 3D Point Clouds to Pose-Normalised Depth Maps
We consider the problem of generating either pairwise-aligned or pose-normalised depth maps from noisy 3D point clouds in a relatively unrestricted poses. Our system is deployed in a 3D face alignment application and consists of the following four stages: (i) data filtering, (ii) nose tip identification and sub-vertex localisation, (iii) computation of the (relative) face orientation, (iv) generation of either a pose aligned or a pose normalised depth map. We generate an implicit radial basis function (RBF) model of the facial surface and this is employed within all four stages of the process. For example, in stage (ii), construction of novel invariant features is based on sampling this RBF over a set of concentric spheres to give a spherically-sampled RBF (SSR) shape histogram. In stage (iii), a second novel descriptor, called an isoradius contour curvature signal, is defined, which allows rotational alignment to be determined using a simple process of 1D correlation. We test our system on both the University of York (UoY) 3D face dataset and the Face Recognition Grand Challenge (FRGC) 3D data. For the more challenging UoY data, our SSR descriptors significantly outperform three variants of spin images, successfully identifying nose vertices at a rate of 99.6%. Nose localisation performance on the higher quality FRGC data, which has only small pose variations, is 99.9%. Our best system successfully normalises the pose of 3D faces at rates of 99.1% (UoY data) and 99.6% (FRGC data)
Assessing Trump's presidential endorsements while in and out of office (2018â2022)
In the 2022 midterm elections, Donald Trump made a slew of high-profile endorsements, continuing a trend of prolific endorsement activity established during his time in office. While existing works have largely focused on presidential campaigning in congressional races from sitting presidents, little is known about the effects of this continued activity once a president has left office. This paper therefore assesses trends in President Trump's endorsements across three election cycles (2018â2022), testing whether the types of candidates that Trump chose to endorse and the engagement and electoral effects of these endorsements changed over time. Across all election cycles, his endorsements produced little benefit for candidates in the general election. Endorsed candidates did not benefit financially and collectively received an aggregate vote share penalty of approximately 1.5 percentage points. However, endorsed candidates received a consistent and substantial electoral benefit in Republican primary elections, with these benefits growing marginally over time. Trump's endorsements came increasingly early in the election cycle, with an increased focus on backing likely winners and rewarding political allies during the primaries. As such, significant changes in the types of candidates receiving endorsements after President Trump left office highlight an important shift in post-presidency endorsement strategy, where partisan electoral goals were secondary to a strategic focus on retaining personal influence within the Republican party
Continuity or change in business representation in Britain? An assessment of the Heseltine initiatives of the 1990s
Britain has a fragmented, overlapping, and underresourced system of business representation. Attempts at reform, however, have proved difficult and largely unsuccessful. A coherent and logical system is relevant, in terms of both an effective dialogue between government and business, and the promotion of competitiveness and productivity. Through interviews and archival evidence, I look at how government has attempted to reform business associations. The main focus is the Heseltine initiatives of the 1990s: I outline the various initiatives taken, reveal the extent to which policy represented continuity or change, and consider whether the initiatives were effective. I show that they had a degree of success but that they would have made greater impact if they had been sustained over a longer period of time. A consideration of the historical context, moreover, suggests there may be limits to the role of government intervention in business association reform
Harnessing Polyhydroxyalkanoates and Pressurized Gyration for Hard and Soft Tissue Engineering
Organ dysfunction is a major cause of morbidity and mortality. Transplantation is typically the only definitive cure, challenged by the lack of sufficient donor organs. Tissue engineering encompasses the development of biomaterial scaffolds to support cell attachment, proliferation, and differentiation, leading to tissue regeneration. For efficient clinical translation, the forming technology utilized must be suitable for mass production. Herein, uniaxial polyhydroxyalkanoate scaffolds manufactured by pressurized gyration, a hybrid scalable spinning technique, are successfully used in bone, nerve, and cardiovascular applications. Chorioallantoic membrane and in vivo studies provided evidence of vascularization, collagen deposition, and cellular invasion for bone tissue engineering. Highly efficient axonal outgrowth was observed in dorsal root ganglion-based 3D ex vivo models. Human induced pluripotent stem cell derived cardiomyocytes exhibited a mature cardiomyocyte phenotype with optimal calcium handling. This study confirms that engineered polyhydroxyalkanoate-based gyrospun fibers provide an exciting and unique toolbox for the development of scalable scaffolds for both hard and soft tissue regeneration
A prospective study of consecutive emergency medical admissions to compare a novel automated computer-aided mortality risk score and clinical judgement of patient mortality risk
YesObjectives: To compare the performance of a validated automatic computer-aided risk of mortality (CARM) score versus medical judgement in predicting the risk of in-hospital mortality for patients following emergency medical admission. Design: A prospective study. Setting: Consecutive emergency medical admissions in York hospital. Participants: Elderly medical admissions in one ward were assigned a risk of death at the first post-take ward round by consultant staff over a 2-week period. The consultant medical staff used the same variables to assign a risk of death to the patient as the CARM (age, sex, National Early Warning Score and blood test results) but also had access to the clinical history, examination findings and any immediately available investigations such as ECGs. The performance of the CARM versus consultant medical judgement was compared using the c-statistic and the positive predictive value (PPV). Results: The in-hospital mortality was 31.8% (130/409). For patients with complete blood test results, the c-statistic for CARM was 0.75 (95% CI: 0.69 to 0.81) versus 0.72 (95% CI: 0.66 to 0.78) for medical judgements (p=0.28). For patients with at least one missing blood test result, the c-statistics were similar (medical judgements 0.70 (95% CI: 0.60 to 0.81) vs CARM 0.70 (95% CI: 0.59 to 0.80)). At a 10% mortality risk, the PPV for CARM was higher than medical judgements in patients with complete blood test results, 62.0% (95% CI: 51.2 to 71.9) versus 49.2% (95% CI: 39.8 to 58.5) but not when blood test results were missing, 50.0% (95% CI: 24.7 to 75.3) versus 53.3% (95% CI: 34.3 to 71.7). Conclusions: CARM is comparable with medical judgements in discriminating in-hospital mortality following emergency admission to an elderly care ward. CARM may have a promising role in supporting medical judgements in determining the patient's risk of death in hospital. Further evaluation of CARM in routine practice is required.Supported by the Health Foundation, National Institute for Health Research (NIHR) Yorkshire and Humberside Patient Safety Translational Research Centre (NIHR YHPSTRC)
Time-dependent probability density functions and information geometry in stochastic logistic and Gompertz models
A probabilistic description is essential for understanding growth processes in non-stationary states. In this paper, we compute time-dependent probability density functions (PDFs) in order to investigate stochastic logistic and Gompertz models, which are two of the most popular growth models. We consider different types of short-correlated multiplicative and additive noise sources and compare the time-dependent PDFs in the two models, elucidating the effects of the additive and multiplicative noises on the form of PDFs. We demonstrate an interesting transition from a unimodal to a bimodal PDF as the multiplicative noise increases for a fixed value of the additive noise. A much weaker (leaky) attractor in the Gompertz model leads to a significant (singular) growth of the population of a very small size. We point out the limitation of using stationary PDFs, mean value and variance in understanding statistical properties of the growth in non-stationary states, highlighting the importance of time-dependent PDFs. We further compare these two models from the perspective of information change that occurs during the growth process. Specifically, we define an infinitesimal distance at any time by comparing two PDFs at times infinitesimally apart and sum these distances in time. The total distance along the trajectory quantifies the total number of different states that the system undergoes in time, and is called the information length. We show that the time-evolution of the two models become more similar when measured in units of the information length and point out the merit of using the information length in unifying and understanding the dynamic evolution of different growth processes
Geometric structure and geodesic in a solvable model of nonequilibrium process
We investigate the geometric structure of a nonequilibrium process and its geodesic solutions. By employing an exactly solvable model of a driven dissipative system (generalized nonautonomous Ornstein-Uhlenbeck process), we compute the time-dependent probability density functions (PDFs) and investigate the evolution of this system in a statistical metric space where the distance between two points (the so-called information length) quantifies the change in information along a trajectory of the PDFs. In this metric space, we find a geodesic for which the information propagates at constant speed, and demonstrate its utility as an optimal path to reduce the total time and total dissipated energy. In particular, through examples of physical realizations of such geodesic solutions satisfying boundary conditions, we present a resonance phenomenon in the geodesic solution and the discretization into cyclic geodesic solutions. Implications for controlling population growth are further discussed in a stochastic logistic model, where a periodic modulation of the diffusion coefficient and the deterministic force by a small amount is shown to have a significant controlling effect
Personalised service? Changing the role of the government librarian
Investigates the feasibility of personalised information service in a government department. A qualitative methodology explored stakeholder opinions on the remit, marketing, resourcing and measurement of the service. A questionnaire and interviews gathered experiences of personalised provision across the government sector. Potential users were similarly surveyed to discuss how the service could meet their needs. Data were analysed using coding techniques to identify emerging theory. Lessons learned from government librarians centred on clarifying requirements, balancing workloads and selective marketing. The user survey showed low usage and awareness of existing specialist services, but high levels of need and interest in services repackaged as a tailored offering. Fieldwork confirmed findings from the literature on the scope for adding value through information management advice, information skills training and substantive research assistance and the need to understand business processes and develop effective partnerships. Concluding recommendations focus on service definition, strategic marketing, resource utilisation and performance measurement
Local industrial strategy and skills policy in England: Assessing the linkages and limitations â a case study of the Sheffield City Deal
This paper examines changes in local economic development policy which occurred between 2010 and 2015, with a focus on the relationship between industrial strategy and skills policy. Under the Coalition Government, Local Enterprise Partnerships were established and tasked with facilitating local growth, and to do so many identified a set of (potential) growth sectors for industrial strategy to support. These sectors tended to be drawn from a relatively narrow range of industries which therefore often excluded a large proportion of the local economy. An important focus of the support for growth sectors for many has been through an ambition to influence the local skills system. Skills policy more broadly has been an important dimension of devolution, and a number of City Deals have included elements of skills policy. Echoing previous national policy however, the focus of local concerns with skills under devolution has been framed largely with reference to skills gaps and shortages. While specific skills gaps and shortages can be identified, this paper questions whether this default position is reflected widely, and as such, if a narrow focus on skills supply is a sufficient approach. It is argued that to support local growth across a broad base, greater attention needs to be paid to stimulating employer demand for skills through better integrating industrial and innovation policy with skills policymaking across a wider section of the local economy. To support these arguments we present a case study of the Sheffield City Deal
A rare association of rheumatoid arthritis and primary biliary cirrhosis treated with rituximab: a case report
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