The Conundrum of the Stock Concept—Are Nature and Nurture Definable in Fishery Science?

1981 ◽  
Vol 38 (12) ◽  
pp. 1479-1480 ◽  
Author(s):  
Henry E. Booke

The definition of the word stock, as applied in fishery science, is presented in general and in precise forms. The general definition is a species group, or population, of fish that maintains and sustains itself over time in a definable area. In a more precise manner, stock (genotypic) is defined as a population of fish maintaining and sustaining Castle–Hardy–Weinberg equilibrium. If a genetic basis is not available for stock characterization, then a phenotypic stock definition has to be recognized as a population of fish maintaining characteristics which are expressed in one or more ways, depending on the type or nature of environment of domicile.Key words: fish stocks, definition

2002 ◽  
Vol 10 (03) ◽  
pp. 207-223
Author(s):  
DIEGO MEDAN ◽  
NORBERTO BARTOLONI

A genetic model was designed to depict what the resilience of host-pollinator interactions may be according to well known genetic rules and assuming an underlying genetic basis for (a) the attraction that flowers exert on pollinators, and (b) the fitness gain by the pollinator from visiting a flower. We explore the possible trajectories that a plant-pollinator system describes under certain bound conditions determined by a whole complex of attractiveness and reward scores. Such scores represent genetic relations between two diallelic loci assumed to control both traits. To see how the system would behave over time we created eight different scenarios, differing in the orientation they impose on the system. Half of these situations are of a reinforcing type (indicating a similar input both for attractiveness and rewards) and the remaining ones are conflicting (indicating opposite inputs). A numerical simulation was carried over seventy-five generations starting from Hardy–Weinberg equilibrium populations. We detected some general behavioral patterns in the final structure of frequencies. One of these may be viewed as a resilient type of structure (i.e., without memory of the initial population frequencies) which we hypothesize, may reflect the typical attraction-reward structure generally observed in nature. Another pattern is characterized by a pronounced lose of heterozygotes in the final structure, caused by the fixation of the most attractive phenotypes at the expense of the least attracting ones, independently of the pollinator genotype.


Author(s):  
Ernest Davis

This chapter discusses the use of transition graphs for reasoning about continuous spatial change over time. The chapter first presents a general definition of a transition graph for a partition of a topological space. Then it defines the path-connected and the homogeneous refinements of such a partition. The qualitative behavior of paths through the space corresponds to the structure of paths through the associated transition graphs, and of associated interval label sequences, and the authors prove a number of metalogical theorems that characterize these correspondences in terms of the expressivity of associated first-order languages. They then turn to specific real-world problems and show how this theory can be applied to domains such as rigid objects, strings, and liquids.


Author(s):  
Galen Strawson

This chapter examines the difference between John Locke's definition of a person [P], considered as a kind of thing, and his definition of a subject of experience of a certain sophisticated sort [S]. It first discusses the equation [P] = [S], where [S] is assumed to be a continuing thing that is able to survive radical change of substantial realization, as well as Locke's position about consciousness in relation to [P]'s identity or existence over time as [S]. It argues that Locke is not guilty of circularity because he is not proposing consciousness as the determinant of [S]'s identity over time, but only of [S]'s moral and legal responsibility over time. Finally, it suggests that the terms “Person” and “Personal identity” pull apart, in Locke's scheme of things, but in a perfectly coherent way.


1990 ◽  
Vol 17 (2) ◽  
pp. 113-123 ◽  
Author(s):  
LuAnn Bean ◽  
Deborah W. Thomas

Determining what should be considered a material item has been a problem for both the accounting profession and the courts. By reviewing the court cases involving the issue of materiality, the authors have determined where differences in the materiality standard as applied by the courts exist. The judicial definition of materiality has developed over time, and current trends with important variations are observed. Based upon the authors' analysis, the following judicial definition of materiality, with its possible variations, is suggested: Would the reasonable (or speculative) investor (or layman) consider important (or be influenced by) this information in determining his course of action?


Author(s):  
James G. March

Humans use reasons to shape and justify choices. In the process, trade-offs seem essential and often inevitable. But trade-offs involve comparisons, which are problematic both across values and especially over time. Reducing disparate values to a common metric (especially if that metric is money) is often problematic and unsatisfactory. Critically, it is not that values just shape choices, but that choices themselves shape values. This endogeneity of values makes an unconditional normative endorsement of modern decision-theoretic rationality unwise. This is a hard problem and there is no escaping the definition of good values, that is, those that make humans better. This removes the wall between economics and philosophy. If we are to adopt and enact this perspective, then greater discourse and debate on what matters and not just what counts will be useful and even indispensable.


2016 ◽  
Vol 14 (1) ◽  
pp. 1122-1124 ◽  
Author(s):  
Ricardo Almeida ◽  
Małgorzata Guzowska ◽  
Tatiana Odzijewicz

AbstractIn this short note we present a new general definition of local fractional derivative, that depends on an unknown kernel. For some appropriate choices of the kernel we obtain some known cases. We establish a relation between this new concept and ordinary differentiation. Using such formula, most of the fundamental properties of the fractional derivative can be derived directly.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1633.2-1634
Author(s):  
F. Cosan ◽  
O. M. Gedar

Background:Reactive arthritis (ReA) is defined by 1999 ACR criteria as arthritis preceding a bacterial genitourinary (GUS) or gastrointestinal (GIS) infection in 3 days-6 weeks and evidence of triggering infection. Recently, ReA is classified as SpA and patients who do not fulfill SpA criteria are classified as undifferentiated spondyloarthritis (USpA) according to ASAS/EULAR SpA classification criteria.Objectives:In several case reports which are associated with other infective agents are reported and the definition is extended for some clinicians so that SpA which is occurred after any infection is called as ReA. On the other hand, some researchers still accept the classical definition of ReA. The problem with the heterogeneity of opinions and unstandardized definition of ReA hinders studies about pathogenesis and standardization of treatments. In this study, we aimed to determine the spectrum of the use of the definition of reactive arthritis in publications in PubMed between 2009-2019.Methods:The ReA keyword is searched in PubMed for the years between 2009-2019. 248 different publications have been identified and included in this research. 89 articles, 47 reviews, 108 case reports, 2 guidelines, and 2 editorials reviewed for the definition of ReA.Results:Only 42.7% (106 patients) of these publications meet the classical definition which suggests ReA after only GIS and GUS infections. In 4 (1.6%) of the publications ReA was defined after GIS, GUS and oropharyngeal infections; in 3 (1,2%) of the publications after any bacterial infection; in 9 (3.6%) of the publications after any infection. In 8 (3.2%) of the publications, ReA and USPA was used correspondingly. In 39 (15,7%) of the publications the term agent related, ReA was used without making a general definition for ReA. 79 publications (31,9%) have not defined ReA.According to causative agent and ReA relationship, in 64 (24,6%) general infective agents, in 75 (30,2%) classical agents, in 22 (8,9%) other bacterial agents, in 23 (9,3%) streptococcus, in 10(4%) intravesical BCG, in 6 (2.4%) HIV, in 6 (2.4%) tuberculosis, in 12 (4,8%) clostrudium difficle, in 2 (0.8%) parasites were reported. In 31 (12,5%) of the publications the causative agent for the ReA was unknown, the diagnosis was made clinically.Conclusion:In this study, it is aimed to draw attention terminology intricacy and the need for the standardization of the definition of ReA and USpA. It is clear that to standardize the definition of Rea and USpA is necessary. Between 2009-2019 there are reported cases diagnosed as ReA associated with bacterial infections (especially with Clostridium difficile, streptococcus and tuberculosis infections), and viral infections (by a majority with HIV), and parasitic infections. It is not clear if we need to define them classically or define them as USPA. Another important consideration is the necessity of extended laboratory investigations to find out the real causative agent even if the patient is clinically diagnosed with ReA. The requirement of the differentiation between ReA and USpA must be revealed for therapeutic researches.References:[1]A proposal for the classification of patients for clinical and experimental studies on reactive arthritis. Pacheco-Tena C, Burgos-Vargas R, Vázquez-Mellado J, Cazarín J, Pérez-Díaz JA. J Rheumatol. 1999 Jun;26(6):1338-46.[2]The Assessment of SpondyloArthritis International Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in general. Rudwaleit M, van der Heijde D, Landewé R, Akkoc N, Brandt J, Chou CT, Dougados M, Huang F, Gu J, Kirazli Y, et al. Ann Rheum Dis. 2011;70:25–31.Disclosure of Interests:None declared


Author(s):  
M. Ferrara ◽  
M. Trombetti

AbstractLet G be an abelian group. The aim of this short paper is to describe a way to identify pure subgroups H of G by looking only at how the subgroup lattice $$\mathcal {L}(H)$$ L ( H ) embeds in $$\mathcal {L}(G)$$ L ( G ) . It is worth noticing that all results are carried out in a local nilpotent context for a general definition of purity.


2021 ◽  
Author(s):  
Andrea Marin ◽  
Carla Piazza ◽  
Sabina Rossi

AbstractIn this paper, we deal with the lumpability approach to cope with the state space explosion problem inherent to the computation of the stationary performance indices of large stochastic models. The lumpability method is based on a state aggregation technique and applies to Markov chains exhibiting some structural regularity. Moreover, it allows one to efficiently compute the exact values of the stationary performance indices when the model is actually lumpable. The notion of quasi-lumpability is based on the idea that a Markov chain can be altered by relatively small perturbations of the transition rates in such a way that the new resulting Markov chain is lumpable. In this case, only upper and lower bounds on the performance indices can be derived. Here, we introduce a novel notion of quasi-lumpability, named proportional lumpability, which extends the original definition of lumpability but, differently from the general definition of quasi-lumpability, it allows one to derive exact stationary performance indices for the original process. We then introduce the notion of proportional bisimilarity for the terms of the performance process algebra PEPA. Proportional bisimilarity induces a proportional lumpability on the underlying continuous-time Markov chains. Finally, we prove some compositionality results and show the applicability of our theory through examples.


Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 2006
Author(s):  
Courtney Thompson ◽  
Jean Adams ◽  
Helen Anna Vidgen

(1) Background: The term ‘food literacy’ has gained momentum globally; however, a lack of clarity around its definition has resulted in inconsistencies in use of the term. Therefore, the objective was to conduct a systematic scoping review to describe the use, reach, application and definitions of the term ‘food literacy’ over time. (2) Methods: A search was conducted using the PRISMA-ScR guidelines in seven research databases without any date limitations up to 31 December 2019, searching simply for use of the term ‘food literacy’. (3) Results: Five hundred and forty-nine studies were included. The term ‘food literacy’ was used once in 243 articles (44%) and mentioned by researchers working in 41 countries. Original research was the most common article type (n = 429, 78%). Food literacy was published across 72 In Cites disciplines, with 456 (83%) articles from the last 5 years. In articles about food literacy (n = 82, 15%), review articles were twice as prevalent compared to the total number of articles (n = 10, 12% vs. n = 32, 6%). Fifty-one different definitions of food literacy were cited. (4) Conclusions: ‘Food literacy’ has been used frequently and broadly across differing article types and disciplines in academic literature internationally. However, agreement on a standardised definition of food literacy endorsed by a peak international agency is needed in order to progress the field.


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