1,654 research outputs found
A Discrete Version of the Inverse Scattering Problem and the J-matrix Method
The problem of the Hamiltonian matrix in the oscillator and Laguerre basis
construction from the S-matrix is treated in the context of the algebraic
analogue of the Marchenko method.Comment: 11 pages. The Laguerre basis case is adde
Other‐Sacrificing Options
I argue that you can be permitted to discount the interests of your adversaries even though doing so would be impartially suboptimal. This means that, in addition to the kinds of moral options that the literature traditionally recognises, there exist what I call other-sacrificing options. I explore the idea that you cannot discount the interests of your adversaries as much as you can favour the interests of your intimates; if this is correct, then there is an asymmetry between negative partiality toward your adversaries and positive partiality toward your intimates
Asymmetries in the Value of Existence
According to asymmetric comparativism, it is worse for a person to exist with a miserable life than not to exist, but it is not better for a person to exist with a happy life than not to exist. My aim in this paper is to explain how asymmetric comparativism could possibly be true. My account of asymmetric comparativism begins with a different asymmetry, regarding the (dis)value of early death. I offer an account of this early death asymmetry, appealing to the idea of conditional goods, and generalize it to explain how asymmetric comparativism could possibly be true. I also address the objection that asymmetric comparativism has unacceptably antinatalist implications
NN potentials from inverse scattering in the J-matrix approach
An approximate inverse scattering method [7,8] has been used to construct
separable potentials with the Laguerre form factors. As an application, we
invert the phase shifts of proton-proton in the  and 
channels and neutron-proton in the  channel elastic scattering. In
the latter case the deuteron wave function of a realistic  potential was
used as input.Comment: LaTex2e, 17 pages, 3 Postscript figures; corrected typo
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Changes in neuromuscular structure and functions of human colon during ageing are region-dependent
Objective: To determine if human colonic neuromuscular functions decline with increasing age.Design: Looking for non-specific changes in neuromuscular function, a standard burst of electrical field stimulation (EFS) was used to evoke neuronally mediated (cholinergic/nitrergic) contractions/relaxations in ex vivomuscle strips of human ascending and descending colon, aged 35–91 years (macroscopically normal tissue; 239 patients undergoing cancer resection). Then, to understand mechanisms of change, numbers and phenotype of myenteric neurons (30 306 neurons stained with different markers), densities of intramuscular nerve fibres (51 patients in total) and pathways involved in functional changes were systematically investigated (by immunohistochemistry and use of pharmacological tools) in elderly (≥70 years) and adult (35–60 years) groups.Results: With increasing age, EFS was more likely to evoke muscle relaxation in ascending colon instead of contraction (linear regression: n=109, slope 0.49%±0.21%/year, 95% CI ), generally uninfluenced by comorbidity or use of medications. Similar changes were absent in descending colon. In the elderly, overall numbers of myenteric and neuronal nitric oxide synthaseimmunoreactive neurons and intramuscular nerve densities were unchanged in ascending and descending colon, compared with adults. In elderly ascending, not descending, colon numbers of cell bodies exhibiting choline acetyltransferase immunoreactivity increased compared with adults (5.0±0.6 vs 2.4±0.3 neurons/mm myenteric plexus, p=0.04). Cholinergically mediated contractions were smaller in elderly ascending colon compared with adults (2.1±0.4 and 4.1±1.1 g-tension/gtissue during EFS; n=25/14; p=0.04); there were no changes in nitrergic function or in ability of the muscle to contract/relax. Similar changes were absent in descending colon.Conclusion: In ascending not descending colon, ageing
impairs cholinergic function
Research review: young people leaving care
This paper reviews the international research on young people leaving care. Set in the context of a social exclusion framework, it explores young people's accelerated and compressed transitions to adulthood, and discusses the development and classification of leaving care services in responding to their needs. It then considers the evidence from outcome studies and argues that adopting a resilience framework suggests that young people leaving care may fall into three groups: young people 'moving on', 'survivors' and 'victims'. In concluding, it argues that these three pathways are associated with the quality of care young people receive, their transitions from care and the support they receive after care
Agent-based Social Psychology: from Neurocognitive Processes to Social Data
Moral Foundation Theory states that groups of different observers may rely on
partially dissimilar sets of moral foundations, thereby reaching different
moral valuations. The use of functional imaging techniques has revealed a
spectrum of cognitive styles with respect to the differential handling of novel
or corroborating information that is correlated to political affiliation. Here
we characterize the collective behavior of an agent-based model whose inter
individual interactions due to information exchange in the form of opinions are
in qualitative agreement with experimental neuroscience data. The main
conclusion derived connects the existence of diversity in the cognitive
strategies and statistics of the sets of moral foundations and suggests that
this connection arises from interactions between agents. Thus a simple
interacting agent model, whose interactions are in accord with empirical data
on conformity and learning processes, presents statistical signatures
consistent with moral judgment patterns of conservatives and liberals as
obtained by survey studies of social psychology.Comment: 11 pages, 4 figures, 2 C codes, to appear in Advances in Complex
  System
Simulating NIRS and MRS Measurements During Cerebral Hypoxia-Ischaemia in Piglets Using a Computational Model
We present a group analysis of the changes in cerebral haemodynamics, and the oxidation state of cytochrome-c-oxidase measured using broadband near-infrared spectroscopy (NIRS) and intracellular pH measured by phosphorous ((31)P) magnetic resonance spectroscopy (MRS) during and after cerebral hypoxia-ischaemia (HI) in 15 piglets. We use a previously published computational model of cerebral metabolism in the piglet [1] to integrate these measurements and simulate HI. We successfully simulate changes in cellular metabolism including shifts in intracellular pH observed in the piglet brain during HI. In this process, we optimise physiological parameters in the model identified through sensitivity analysis (such as the rate of glucose metabolism and intracellular lactate concentration), to fit simulated and measured data. The model fits the data reasonably and suggests a 20 % drop in glucose consumption, a ~65 % increase in lactate concentration and ~35 % drop in the cerebral metabolic rate of oxygen (CMRO₂) during HI
Generating Muscle Driven Arm Movements Using Reinforcement Learning
This project focuses on using Reinforcement Learning to optimize arm dynamics through muscle control for desired trajectories. The goal of this project was to create a tool that can be used to gain a better understanding of the arm’s muscles and collect information that is useful in many other disciplines such as biomechanics, anthropology, medicine and robotics. I developed biologically realistic models of primate arm\u27s using Stanford’s SimTK software, an open-source tool for modeling musculoskeletal structures. I then made use of Differential Dynamic Programming in order to generate novel movements from first principles and optimize motion over a specified trajectory. Lastly, I demonstrated the usefulness of this tool by examining its effectiveness in discovering the consequences of different muscle groups on the optimal behavior policy
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