The Temporality Effect in Thinking about What Might Have Been

When people think about what might have been, they construct a mental representation of the actual state of affairs, and they generate an imaginary alternative by carrying out minimal mutations to it. When they think about how an undesirable outcome might have been avoided, they mutate the events leading to the outcome in regular ways, for example, they undo the more recent event in a series of independent events. W e describe a computer simulation of the cognitive processes that underlie these effects of temporality on counterfactual thinking that is based on the idea that reasoners construct contextualized models. W e report the results of two experiments that show that the temporality effect arises because the first event provides the context against which subsequent events are interpreted. The experiments show that when the contextualizing role of the first event is decoupled from its temporal order the effect is eliminated, for both bad and good outcomes. The results rule out an alternative explanation based on the idea that the more recent event is 'fresh' in mind. The context effect in temporal mutability may shed light on the remaining primary phenomena of counterfactual thinking

Evidence of Tamarix hybrids in South Africa, as inferred by nuclear ITS and plastid trnS–trnG DNA sequences

AbstractTamarix usneoides (Tamaricaceae) is a species native to southern Africa where it is currently being used in the mines for phytoremediation. Tamarix aphylla, Tamarix ramosissima, Tamarix chinensis, and Tamarix parviflora have been reported as exotic species in South Africa, with T. ramosissima declared invasive. The alien invasive T. ramosissima is hypothesized to be hybridizing with the indigenous T. usneoides. Accurate identification of Tamarix is of great importance in southern Africa because of the invasive potential of T. ramosissima and also the potential usefulness of T. usneoides. In this study, nuclear DNA sequence markers (ITS1 and ITS2 regions), together with the plastid marker trnS–trnG, are used to identify the genetic distinctiveness of Tamarix species and their putative hybrids. Phylogenies based on the ITS and trnS–trnG regions revealed that the indigenous T. usneoides is genetically distinct from the exotic species, which, however, could not clearly be separated from their closely related hybrids. The lack of congruence (p>0.0001) between the ITS and trnS–trnG phylogenies suggests that there is high incidence of hybridization in Tamarix populations in South Africa. Importantly, molecular diagnosis of Tamarix was able to identify hybrids using polymorphisms and phylogenetic signals. Close to 45% of Tamarix genotypes were hybrids with more than 50% of them occurring on the mines. Spread of Tamarix hybrids in South Africa through phytoremediation could enhance invasiveness. Therefore, the outcome of this study will ensure that only pure indigenous T. usneoides is propagated for planting on the mines in South Africa and that a proper control measure for the alien invasive Tamarix is used. Interestingly, the molecular diagnosis of Tamarix species supported the preliminary morphological identification of the species using eight key characters. However, the molecular markers used were not informative enough to separate hybrids from their closely related parent species. Hybrids were more reliably identified using polymorphisms than morphological features

A Mathematical Model of Liver Cell Aggregation In Vitro

The behavior of mammalian cells within three-dimensional structures is an area of intense biological research and underpins the efforts of tissue engineers to regenerate human tissues for clinical applications. In the particular case of hepatocytes (liver cells), the formation of spheroidal multicellular aggregates has been shown to improve cell viability and functionality compared to traditional monolayer culture techniques. We propose a simple mathematical model for the early stages of this aggregation process, when cell clusters form on the surface of the extracellular matrix (ECM) layer on which they are seeded. We focus on interactions between the cells and the viscoelastic ECM substrate. Governing equations for the cells, culture medium, and ECM are derived using the principles of mass and momentum balance. The model is then reduced to a system of four partial differential equations, which are investigated analytically and numerically. The model predicts that provided cells are seeded at a suitable density, aggregates with clearly defined boundaries and a spatially uniform cell density on the interior will form. While the mechanical properties of the ECM do not appear to have a significant effect, strong cell-ECM interactions can inhibit, or possibly prevent, the formation of aggregates. The paper concludes with a discussion of our key findings and suggestions for future work

Tracing KAM tori in presymplectic dynamical systems

We present a KAM theorem for presymplectic dynamical systems. The theorem has a " a posteriori " format. We show that given a Diophantine frequency $\omega$ and a family of presymplectic mappings, if we find an embedded torus which is approximately invariant with rotation $\omega$ such that the torus and the family of mappings satisfy some explicit non-degeneracy condition, then we can find an embedded torus and a value of the parameter close to to the original ones so that the torus is invariant under the map associated to the value of the parameter. Furthermore, we show that the dimension of the parameter space is reduced if we assume that the systems are exact.Comment: 33 pages and one figur

DNA polymorphisms in Merino and Churra Lebrijana sheep breeds

The Merino and Churra Lebrijana ovine breeds are two of the most important sheeps developed in Spain. In the first case, the study of its genetic characteristics is justified by the importance it has have in the origin of other wool breeds. The Churra Lebrijana sheep breed is next the extinction therefore it is necessary to begin a conservation programme of its genetic resources.Las razas ovinas Merino y Churra son dos de las más importantes ovejas explotadas en España. En el primer caso, el estudio de sus características genéticas se justifica por la importancia que ha tenido en el origen de otras razas ovinas productoras de lana. La raza Churra Lebrijana se encuentra próxima a la extinción por lo que es necesario iniciar programas para la recuperación de sus recursos genéticos

Towards environments that have a sense of humor

Humans have humorous conversations and interactions. Nowadays our real life existence is integrated with our life in social media, videogames, mixed reality and physical environments that sense our activities and that can adapt appearance and properties due to our activities. There are other inhabitants in these environments, not only human, but also virtual agents and social robots with which we interact and who decide about their participation in activities. In this paper we look at designing humor and humor opportunities in such environments, providing them with a sense of humor, and able to recognize opportunities to generate humorous interactions or events on the fly. Opportunities, made possible by introducing incongruities, can be exploited by the environment itself, or they can be communicated to its inhabitants

A pre-post study of behavioural determinants and practice change in Ugandan clinical officers

Background. Understanding the drivers of ‘provider behaviour’ has been highlighted as one of the six domains of behaviour change in strengthening healthcare systems.Objectives. To assess changes in healthcare provider behaviour, i.e. use of the Airway, Breathing, Circulation, Disability, Exposure (ABCDE) approach in acute illness management, after participating in a 1-day course on the assessment and management of acutely ill patients. We aimed to assess whether changes in psychological determinants of the ABCDE approach were associated with changes in the use of the approach.Methods. We used a pre-post design to study self-reported change in behaviour after a 1-day training course from pre-course to follow-up 1 month later. We also measured psychological determinants of behaviour immediately before and after and at 1-month follow-up. We explored if changes in psychological determinants were associated with change in practice 1 month later.Results. We found the following: firstly, use of the ABCDE approach increased at 1 month post-course from a median use of 50 - 90%. Secondly, the increase in the ABCDE approach was associated with a positive change in only one of the determinants of practice from pre- to post-course: perception of environmental determinants (r=0.323; p<0.05). Finally, there were no other significant associations with practice change or practice at follow-up.Conclusions. Change in perceptions of availability of resources was associated with increased use of an ABCDE approach, but evidence was limited owing to the pre-post design

Population genetic analysis of brazilian peach breeding germplasm.

ABSTRACT Peach has great economic and social importance in Brazil. Diverse sources of germplasm were used to introduce desirable traits in the Brazilian peach breeding pool, composed mainly by local selections and accessions selected from populations developed by the national breeding programs, adapted to subtropical climate, with low chill requirement, as well as accessions introduced from several countries. In this research, we used SSR markers, selected by their high level of polymorphism, to access genetic diversity and population structure of a set composed by 204 peach selected genotypes, based on contrasting phenotypes for valuable traits in peach breeding. A total of 80 alleles were obtained, giving an average of eight alleles per locus. In general, the average value of observed heterozygosity (0.46) was lower than the expected heterozygosity (0.63). STRUCTURE analysis assigned 162 accessions splitted into two subpopulations based mainly on their flesh type: melting (96) and non-melting (66) flesh cultivars. The remaining accessions (42) could not be assigned under the 80% membership coefficient criteria. Genetic variability was greater in melting subpopulation compared to non-melting. Additionally, 55% of the alleles present in the breeding varieties were also present in the founder varieties, indicating that founding clones are well represented in current peach cultivars and advanced selections developed. Overall, this study gives a first insight of the peach genetic variability available and evidence for population differentiation (structure) in this peach panel to be exploited and provides the basis for genome-wide association studies

Automated Detection of Coronal Loops using a Wavelet Transform Modulus Maxima Method

We propose and test a wavelet transform modulus maxima method for the au- tomated detection and extraction of coronal loops in extreme ultraviolet images of the solar corona. This method decomposes an image into a number of size scales and tracks enhanced power along each ridge corresponding to a coronal loop at each scale. We compare the results across scales and suggest the optimum set of parameters to maximise completeness while minimising detection of noise. For a test coronal image, we compare the global statistics (e.g., number of loops at each length) to previous automated coronal-loop detection algorithms