The relationship between perseverative thinking, proactive control, and inhibition in psychological distress: a study in a women's cohort.

Cognitive control is a core feature of several mental disorders. A recent account poses that health problems may derive from proactive forms of cognitive control that maintain stress representation over time. The working hypothesis of the present study is that psychological distress is caused by the tendency to select a particular maladaptive self-regulation strategy over time, namely perseverative thinking, rather than by transient stimulus-response patterns. To test this hypothesis, we asked 84 women to carry out a battery of standardized questionnaires regarding their tendency to undertake perseverative thinking and their level of psychological distress, followed by cognitive tasks measuring the tendency to use proactive versus reactive control modality and disinhibition. Through a series of mediation analyses, we demonstrate that the tendency to use proactive control correlates with psychological distress and that this relation is mediated by perseverative thinking. Moreover, we show that the relation between low inhibitory control and psychological stress is more strongly mediated by perseverative thinking than impulsiveness, a classical construct that focuses on more transient reactions to stimuli. The present results underline the importance of considering psychological distress as the consequence of a maladaptive way of applying control over time, rather than the result of a general deficit in cognitive control abilities. [Abstract copyright: © 2023. The Author(s).

Twisted memories: Addiction-related engrams are strengthened by desire thinking.

Associative learning plays a central role in addiction by reinforcing associations between environmental cues and addiction-related information. Unsupervised learning models posit that memories are adjusted based on how strongly these representations are coactivated during the retrieval process. From a different perspective, clinical models of addiction posit that the escalation and persistence of craving may depend on desire thinking, a thinking style orienting to prefigure information about positive addiction-related experiences. In the present work, we tested the main hypothesis that desire thinking is a key factor in the strengthening of addiction-related associations. A group of adult smoking volunteers (N = 26) engaged in a period of desire thinking before performing an associative learning task in which neutral words (cues) were shown along with images (smoking-related vs. neutral context) at different frequencies. Two retrieval tests were administered, one immediately after encoding and the other after 24 h, to test how the recall of associations changed as a function of retention interval. Two control groups, smokers (N = 21) and non-smokers (N = 22), performed a similar procedure, with a neutral imagination task replacing desire thinking. Participants who engaged in desire thinking increased their performance from the first to the second retrieval test only for the most frequent smoking-related associations. Crucially, this selective effect was not observed in the two control groups. These results provide behavioral evidence in support of the idea that desire thinking plays a role in strengthening addiction-related associations. Thus, this thinking process may be considered a target for reconsolidation-based conceptualizations of, and treatments for, addiction. [Abstract copyright: Copyright © 2023 Elsevier Ltd. All rights reserved.

A new distributed protocol for consensus of discrete-time systems

In this paper, a new distributed protocol is proposed to force consensus in a discrete-time network of scalar agents with an arbitrarily assignable convergence rate. Several simulations validate the performances and the improvements with respect to more standard protocols

Design principles for long-range energy transfer at room temperature

Typical room temperature conditions hinder ballistic long-range transfer of excitations, rendering quantum phenomena unimportant as potential tools for the design of efficient and controllable energy transfer over significant time and length scales. However, it is well-known that many properties of macroscopic systems depend on the quantum properties of minimal repeating units and, as we show here, excitonic energy transfer is no exception. With the support of an exactly solvable model, we are able to show how exciton delocalization and the ensuing formation of dark states within unit cells can be harnessed to support classical propagation over macroscopic distances. We specifically discuss the role of such factors in nano-fabricated arrays of bacterial photosynthetic complexes via extensive simulations. This allows us to resolve the to-date unexplained experimental observation of exciton diffusion lengths in such arrays in terms of an interplay between intra-unit cell thermalization and delocalization, which conspire to create and use robust dark states at room temperature.Comment: Revised presentation and new title, main results unchanged, 11+10 pages, 3+5 figure

Multistable composite plates with piecewise variation of lay-up in the planform

a b s t r a c t The non-linear out-of-plane displacements of partially unsymmetric laminates are modelled using both finite element analysis and an analytical method. Attention is focused on the effects that thermal stresses have on the potential multiple shapes of a composite structure. The paper extends previous analytical models which could only take into account ''free-free" boundary conditions. The shape functions that model the out-of-plane displacements are modified to include variations of the curvatures within the domain. The new analytical formulation is compared with literature and finite element analysis for a square plate and then it is tested for laminates with piecewise variation of lay-up in the planform. The results are validated against finite element analysis and experimental tests and a good correlation is obtained. Finally, a parametric study is made on the effect of changing the fibres orientation and the laminate thickness. The results confirm that it is possible to introduce bi-stable composites within structures to obtain systems that are both flexible and stiff depending on the loading environment

A fast and cost-effective approach to develop and map EST-SSR markers: oak as a case study

Background: Expressed Sequence Tags (ESTs) are a source of simple sequence repeats (SSRs) that can be used to develop molecular markers for genetic studies. The availability of ESTs for Quercus robur and Quercus petraea provided a unique opportunity to develop microsatellite markers to accelerate research aimed at studying adaptation of these long-lived species to their environment. As a first step toward the construction of a SSR-based linkage map of oak for quantitative trait locus (QTL) mapping, we describe the mining and survey of EST-SSRs as well as a fast and cost-effective approach (bin mapping) to assign these markers to an approximate map position. We also compared the level of polymorphism between genomic and EST-derived SSRs and address the transferability of EST-SSRs in Castanea sativa (chestnut). Results: A catalogue of 103,000 Sanger ESTs was assembled into 28,024 unigenes from which 18.6% presented one or more SSR motifs. More than 42% of these SSRs corresponded to trinucleotides. Primer pairs were designed for 748 putative unigenes. Overall 37.7% (283) were found to amplify a single polymorphic locus in a reference fullsib pedigree of Quercus robur. The usefulness of these loci for establishing a genetic map was assessed using a bin mapping approach. Bin maps were constructed for the male and female parental tree for which framework linkage maps based on AFLP markers were available. The bin set consisting of 14 highly informative offspring selected based on the number and position of crossover sites. The female and male maps comprised 44 and 37 bins, with an average bin length of 16.5 cM and 20.99 cM, respectively. A total of 256 EST-SSRs were assigned to bins and their map position was further validated by linkage mapping. EST-SSRs were found to be less polymorphic than genomic SSRs, but their transferability rate to chestnut, a phylogenetically related species to oak, was higher. Conclusion: We have generated a bin map for oak comprising 256 EST-SSRs. This resource constitutes a first step toward the establishment of a gene-based map for this genus that will facilitate the dissection of QTLs affecting complex traits of ecological importance

Monuments unveiled: Genetic characterization of large old chestnut (Castanea sativa Mill.) trees using comparative nuclear and chloroplast DNA analysis

Large old trees are extraordinary organisms. They not only represent a historical, landscape and environmental heritage of inestimable value, but they also witness a long history of environmental changes and human interventions, and constitute an as yet poorly known reserve of genetic variability which can be considered a great resource for management programs of forest species. This is the first genetic study on Italian, large, old chestnut trees (Castanea sativa Mill.). Ninety-nine trees were surveyed and analysed. For each tree, more than one sample from canopy and root suckers was collected to test for the genetic integrity of the individuals. All samples were genotyped using nine nuclear microsatellite markers (nSSRs) and 106 unique genetic profiles were identified. A Bayesian analysis performed with the software STRUCTURE revealed the occurrence of two main gene pools and unveiled the genetic relationships existing among the genotyped individuals, and with the natural chestnut populations living in proximity. A phylogeographic structure of the plastid diversity was also obtained by the use of DNA sequence variation at two marker regions, revealing different origins and probable connections of the old trees with different glacial refugia. Our results contribute to an improved evaluation of the European chestnut genetic resources and provide useful insights into the species’ history and domestication in Italy. The importance of carefully targeted conservation strategies for these invaluable organisms is reaffirmed

Velocidade de embebição de sementes de soja submetidas a diferentes recobrimentos.

O tratamento de sementes de soja é uma prática utilizada para aumentar o desempenho das sementes, especialmente durante as fases iniciais do ciclo. A utilização do tratamento de sementes com polímeros tem sido uma alternativa para os agricultores por permitir melhor fi xação dos princípios ativos utilizados no tratamento químico. Entretanto, esses produtos não devem afetar as propriedades fisiológicas e físicas das sementes, como a velocidade de embebição. Assim, o objetivo do trabalho foi estudar o efeito de diferentes recobrimentos na velocidade de embebição das sementes de soja. Foram utilizados dois lotes de sementes de soja das cultivares SYN1263 RR e BMX Potência RR, as quais foram submetidas a seis diferentes recobrimentos: 1: Testemunha (ausência de fungicida, inseticida e polímero); 2: Fungicida + Inseticida; 3: Fungicida + Inseticida + Polímero A; 4: Fungicida + Inseticida + Polímero B; 5: Polímero A; 6: Polímero B. O fungicida e o inseticida utilizados foram Derosal Plus (carbendazim + thiram) e Cropstar FloRite 1197 (Nitral Urbana (imidacloprido + tiodicarbe), respectivamente, e os polímeros ) (A) e Laborsan (Laborsan) (B). Para a determinação da velocidade de embebição, as sementes foram dispostas sobre papel germitest umedecido 2,25 vezes o peso do papel seco e incubadas àtemperatura de 20°C, mensurando-se a massa das sementes em intervalos regularesde 1h, durante um período de 24h. De acordo com os resultados, o recobrimento das sementes de soja com os polímeros FloRite1197 (Nitral Urbana) e Laborsan (Laborsan) isolados ou em associação com o fungicida e inseticida não retardam a velocidade de absorção de água