3,279 research outputs found
Fitness differences suppress the number of mating types in evolving isogamous species
Sexual reproduction is not always synonymous with the existence of two morphologically different sexes; isogamous species produce sex cells of equal size, typically falling into multiple distinct self-incompatible classes, termed mating types. A long-standing open question in evolutionary biology is: what governs the number of these mating types across species? Simple theoretical arguments imply an advantage to rare types, suggesting the number of types should grow consistently; however, empirical observations are very different. While some isogamous species exhibit thousands of mating types, such species are exceedingly rare, and most have fewer than 10. In this paper, we present a mathematical analysis to quantify the role of fitness variation—characterized by different mortality rates—in determining the number of mating types emerging in simple evolutionary models. We predict that the number of mating types decreases as the variance of mortality increases
A Decidable Multi-agent Logic for Reasoning About Actions, Instruments, and Norms
We formally introduce a novel, yet ubiquitous, category of norms: norms of instrumentality. Norms of this category describe which actions are obligatory, or prohibited, as instruments for certain purposes. We propose the Logic of Agency and Norms (LAN) that enables reasoning about actions, instrumentality, and normative principles in a multi-agent setting. Leveraging LAN , we formalize norms of instrumentality and compare them to two prevalent norm categories: norms to be and norms to do. Last, we pose principles relating the three categories and evaluate their validity vis-à-vis notions of deliberative acting. On a technical note, the logic will be shown decidable via the finite model property
The Relevance and Efficacy of Marketing in Public and Non-Profit Service Management
The central premise of this article is that public and non-profit service organizations (PNSOs) seek to add value to their multiple stakeholders with their multiple objectives. With the nature and difference of PNSOs in mind, we consider the relevance and the potential impact that a market-led orientation and the various elements of a strategic marketing approach to PNSO management can have on service outcomes and value. We conclude that although PNSOs utilize some management theorems effectively, there is potential for marketing concepts to make a significant contribution to the effective management of public services in contemporary society. © 2012 Copyright Taylor and Francis Group, LLC
Achieving while maintaining:A logic of knowing how with intermediate constraints
In this paper, we propose a ternary knowing how operator to express that the
agent knows how to achieve given while maintaining
in-between. It generalizes the logic of goal-directed knowing how proposed by
Yanjing Wang 2015 'A logic of knowing how'. We give a sound and complete
axiomatization of this logic.Comment: appear in Proceedings of ICLA 201
Meeting report: a hard look at the state of enamel research.
The Encouraging Novel Amelogenesis Models and Ex vivo cell Lines (ENAMEL) Development workshop was held on 23 June 2017 at the Bethesda headquarters of the National Institute of Dental and Craniofacial Research (NIDCR). Discussion topics included model organisms, stem cells/cell lines, and tissues/3D cell culture/organoids. Scientists from a number of disciplines, representing institutions from across the United States, gathered to discuss advances in our understanding of enamel, as well as future directions for the field
Value co-creation in high-involvement services: the animal healthcare sector
Purpose – The purpose of this paper is to investigate the significance of value co-creation to the UK animal healthcare sector from the perspective of the key industry stakeholders: clients, veterinarians and paraprofessionals. Design/methodology/approach – Value co-creation constructs in the sector were identified and measured using a mixed methods approach comprised of qualitative NVivo© thematic analysis of depth interviews (n ¼ 13) and quantitative exploratory factor analysis (EFA) (n ¼ 271). Findings – Qualitative results revealed nine underlying dimensions regarding service delivery in the sector: trustworthiness, communication, value for money, empathy, bespoke, integrated care, tangibles, accessibility and outcome driven service. EFA of professional survey data loaded onto seven latent factors, with strong value co-creation dimensions identified. Research limitations/implications – The sampling process is sufficiently representative and diverse to present meaningful and valuable results, however, surveying should be extended to include the client group. Due to the originality of the research replication of the study will be beneficial to the broader understanding and application of value co-creation to the high-involvement services of animal healthcare. Practical implications – Recognition of the importance of value co-creation to the sector should encourage professional stakeholders to develop and adopt integrated models of service provision and to provide improved levels of service quality. Originality/value – The paper makes an original contribution to knowledge regarding value co-creation in respect of high-involvement service provision. Its findings should be of value to academics interested in value co-creation in service sectors as well as animal healthcare practitioners seeking to offer better value and quality service provision
Recommended from our members
Telephone-delivered compassion-focused therapy for adults with intellectual disabilities: a case series
Purpose: Services are increasingly exploring the use of remote conferencing to deliver psychological interventions, which have become particularly important given the COVID-19 pandemic and infection control guidelines. This paper aims to explore the feasibility, acceptability and preliminary effectiveness of delivering psychological therapy remotely to adults with intellectual disabilities (ID).
Design/methodology/approach: As part of routine practice within an adult ID community health service, this paper develops a six-session programme based on compassion-focused therapy (CFT) and delivered it to six clients. Clients completed the psychological therapy outcome scale for ID 2nd edition, at assessment, pre- and post-therapy, as well as a feasibility and acceptability measure.
Findings: Six clients engaged in telephone therapy; four clients individually, while the remaining two were supported by their caregiver. Most clients found the intervention helpful, enjoyable and were pleased that they received telephone-delivered psychological therapy. A reduction was observed at post-therapy in distress (g = 0.33) and risk (g = 0.69). No difference was reported in psychological well-being. Five clients were subsequently discharged from psychological therapy.
Originality/value: To the knowledge, this is the first study examining the use of telephone therapy (including CFT) for individuals with ID. Findings add to the growing evidence suggesting individuals with ID can benefit from receiving adapted psychological therapies. Research is required to further explore the effectiveness of remote-therapies, who would most likely benefit from this approach and how remote treatments could be used within existing pathways
A Robust Solution Procedure for Hyperelastic Solids with Large Boundary Deformation
Compressible Mooney-Rivlin theory has been used to model hyperelastic solids,
such as rubber and porous polymers, and more recently for the modeling of soft
tissues for biomedical tissues, undergoing large elastic deformations. We
propose a solution procedure for Lagrangian finite element discretization of a
static nonlinear compressible Mooney-Rivlin hyperelastic solid. We consider the
case in which the boundary condition is a large prescribed deformation, so that
mesh tangling becomes an obstacle for straightforward algorithms. Our solution
procedure involves a largely geometric procedure to untangle the mesh: solution
of a sequence of linear systems to obtain initial guesses for interior nodal
positions for which no element is inverted. After the mesh is untangled, we
take Newton iterations to converge to a mechanical equilibrium. The Newton
iterations are safeguarded by a line search similar to one used in
optimization. Our computational results indicate that the algorithm is up to 70
times faster than a straightforward Newton continuation procedure and is also
more robust (i.e., able to tolerate much larger deformations). For a few
extremely large deformations, the deformed mesh could only be computed through
the use of an expensive Newton continuation method while using a tight
convergence tolerance and taking very small steps.Comment: Revision of earlier version of paper. Submitted for publication in
Engineering with Computers on 9 September 2010. Accepted for publication on
20 May 2011. Published online 11 June 2011. The final publication is
available at http://www.springerlink.co
Disease flare of ankylosing spondylitis presenting as reactive arthritis with seropositivity: a case report
<p>Abstract</p> <p>Introduction</p> <p>Concurrent rheumatoid factor seropositivity is occasionally detected in ankylosing spondylitis and often causes confusion in clinical routine. Overlap between various seronegative arthritides is a known but uncommon association. Differentiation of spondyloarthropathy from rheumatoid arthritis is important, since the natural history, complications, treatments and prognosis of the two diseases differ significantly.</p> <p>Case presentation</p> <p>Here, we report the case of a 47-year-old Sri Lankan man who had a long history of intermittent joint pains worsening following a recent episode of self-resolving non-bloody diarrhea. Subsequently, he developed a skin rash suggestive of keratoderma blenorrhagica and circinate balanitis. He had classical radiological evidence of ankylosing spondylosis (previously undiagnosed) associated with human leukocyte antigen B27 antigen, but was positive for rheumatoid factor.</p> <p>Conclusions</p> <p>A disease flare of ankylosing spondylitis prompted by a minor diarrheal illness showing well documented features of reactive arthritis is remarkable. The prognostic implications of seropositivity in spondyloarthritis are discussed.</p
- …