Pretraining the Vision Transformer using self-supervised methods for vision based Deep Reinforcement Learning

The Vision Transformer architecture has shown to be competitive in the computer vision (CV) space where it has dethroned convolution-based networks in several benchmarks. Nevertheless, Convolutional Neural Networks (CNN) remain the preferential architecture for the representation module in Reinforcement Learning. In this work, we study pretraining a Vision Transformer using several state-of-the-art self-supervised methods and assess data-efficiency gains from this training framework. We propose a new self-supervised learning method called TOV-VICReg that extends VICReg to better capture temporal relations between observations by adding a temporal order verification task. Furthermore, we evaluate the resultant encoders with Atari games in a sample-efficiency regime. Our results show that the vision transformer, when pretrained with TOV-VICReg, outperforms the other self-supervised methods but still struggles to overcome a CNN. Nevertheless, we were able to outperform a CNN in two of the ten games where we perform a 100k steps evaluation. Ultimately, we believe that such approaches in Deep Reinforcement Learning (DRL) might be the key to achieving new levels of performance as seen in natural language processing and computer vision. Source code will be available at: https://github.com/mgoulao/TOV-VICRe

Transformative community mental health: perspectives from Portugal and Europe

In the context of the agreement protocol celebrated between APA (American Psychological Association) and OPP (Ordem dos Psicólogos Portugueses) was held in San Francisco, for the 156 th edition of APA annual convention an invited symposium. Were invited speakers the first two of authors of this paper, and the symposium held this same title: Transformative community mental health: perspectives from Portugal and Europe. This symposia was chaired by Amanda Clinton, Director of the Office of International Affairs from APA and was registered the presence of some of the representative from European Associations of Psychologists (including the delegation of OPP), and the presence of the Portuguese diplomatic representation in San Francisco, represented by the Consul General of Portugal in San Francisco. This brief note aims at synthetizing the main ideas flowing from this debate, highlighting the importance of having two Portuguese researchers reporting not only the contemporary views on prevention and promotion but also successful case studies from Portugal and from Europe in the area of Transformative Community Mental Health. Some aspects of the trajectory of scientific knowledge in recent decades and their impact on interventions in the area of Psychology, Public Health, Mental Health and Public Policies will be highlighted, and three case studies related to successful psychological interventions and three successful national public policies will be shortly discussed.info:eu-repo/semantics/publishedVersio

Involving patients and the public In sTatistIcal Analysis pLans (INITIAL): a delphi survey

Background Patient and public involvement (PPI) in trials aims to enhance research by improving its relevance and transparency. Planning for statistical analysis begins at the design stage of a trial within the protocol and is refined and detailed in a Statistical Analysis Plan (SAP). While PPI is common in design and protocol development it is less common within SAPs. This study aimed to reach consensus on the most important and relevant statistical analysis items within an SAP to involve patients and the public. Methods We developed a UK-based, two-round Delphi survey through an iterative consultation with public partners, statisticians, and trialists. The consultation process started with 55 items from international guidance for statistical analysis plans. We aimed to recruit at least 20 participants per key stakeholder group for inclusion in the final analysis of the Delphi survey. Participants were asked to vote on each item using a Likert scale from 1 to 9, where a rating of 1 to 3 was labelled as having ‘limited importance’; 4 to 6 as ‘important but not critical’ and 7 to 9 as ‘critical’ to involve patients and the public. Results from the second round determined consensus on critical items for PPI. Results The consultation exercise led to the inclusion of 15 statistical items in the Delphi survey. We recruited 179 participants, of whom 72% (129: 36 statisticians, 29 patients or public partners, 25 clinical researchers or methodologists, 27 trial managers, and 12 PPI coordinators) completed both rounds. Participants were on average 48 years old, 60% were female, 84% were White, 64% were based in England and 84% had at least five years’ experience in trials. Four items reached consensus regarding critical importance for patient and public involvement: presentation of results to trial participants; summary and presentation of harms; interpretation and presentation of findings in an academic setting; factors impacting how well a treatment works. No consensus was reached for the remaining 11 items. In general, the results were consistent across stakeholder groups. Discussion We identified four critical items to involve patients and the public in statistical analysis plans. The remaining 11 items did not reach consensus and need to be considered in a case-by-case basis with most responders considering patient and public involvement important (but not critical). Our research provides a platform to enable focused future efforts to improve patient and public involvement in trials and enhance the relevance of statistical analyses to patients and the public

A glimpse of climate change impact on C. Arabica L. and C. Canephora Pierre ex A. Froehner physiology: the combined effects of enhanced growth CO2 and temperature.

Summary: The effective impact of climate changes on the coffee plant physiology, promoted by enhanced air [CO2] and global warming remain to be fully elucidated through biological studies. Therefore, this work aims at linking important coffee physiological responses to environmental changes of enhanced growth [CO2] and temperature on genotypes from the two major producing species. Potted plants from C. arabica cv. IPR 108 and of C. canephora cv. Conilon Clone 153 were grown under environmental controlled conditions, either at 380 or 700 ?L CO2 L-1 air, for 1 year, without water, nutrient or root development restrictions. After that the temperature was gradually increased from 25/20 ºC (day/night) up to 42/34 ºC. The long-term impacts of enhanced growth [CO2] and enhanced temperature on the photosynthetic functioning were assessed at 25/20 ºC, 31/25 ºC, 37/30 ºC and 42/34 ºC, through leaf gas exchanges (rates of net photosynthesis, Pn, stomatal conductance, gs, transpiration, Tr, and photosynthetic capacity, Amax), instantaneous water use efficiency (iWUE), fluorescence parameters (photochemical efficiency of the photosystem II under dark, Fv/Fm, and light, Fv?/Fm?, conditions, as well as the photochemical, qP, and non-photochemical, NPQ, quenchings, and quantum yield of the linear electron transport, ?e), photosynthetic pigments (chlorophyll and carotenoids) and some molecules with antioxidant role (ascorbate and ?-tocopherol). The results showed that enhanced [CO2] stimulates photosynthetic functioning, without negative down-regulation. Minor impacts were found in the photochemical performance until 37 ºC, but extensive impacts were shown at 42 ºC, especially in IPR108. Remarkable was the finding that enhanced [CO2] preserved a higher functional status (Pn, Amax, Fo, Fv/Fm) at high temperatures (37 and 42 ºC), what seems quite relevant under the predicted climate changes and global warming scenarios

Thylakoid lipids changes may account for photosynthetic acclimation ability of two coffea species subjected to heat.

Summary: Coffee is one of the world?s most traded agricultural products, and its production could be threatened by global warming. The aim of this work was to evaluate the effects of heat on photosynthetic activity and thylakoid membrane lipid dynamics, on genotypes of the two major coffee producing species. Potted plants from C. arabica L. cv. IPR108 and C. canephora Pierre Ex A. Froehner cv. Conilon Clone 153 were grown for 1 year under controlled conditions of temperature (25/20ºC, day/night), irradiance (650-800 ?mol m-2 s-1), RH (75%), photoperiod (12 h), and 380 ?L CO2 L-1. Thereafter, temperature was gradually raised to 42/34ºC (0.5ºC/ day), with a 7 days stabilization step at 31, 37 and 42ºC. Studies focused modifications of thylakoid lipid composition and photosynthetic performance. In CL153 photosynthetic capacity (Amax) was not affected until 42ºC (40% reduction). In IPR108 it was reduced 35 and 57% at 37ºC at 42ºC, respectively. Thylakoid electron transport rate for photosystems (PS) I and II increased (ca. 10-25%) up to 37ºC in both genotypes. At 42ºC only IPR108 presented depressed activities on PSII (15%) and PSI (18%). Under 37 and 42ºC, CL153 plants presented digalactosyldiacylglycerol (DGDG) (ca. 42%) and monogalactosyldiacylglycerol (MGDG) (28-34%) increases, while IPR108 showed higher MGDG at all temperatures. In CL153 less unsaturated DGDG and phosphatidylglycerol (PG) along with stable or increased DGDG/MGDG ratio, may have contributed to sustain thylakoid electron flow at 37ºC and even 42ºC. IPR108 displayed a strong PG rise at all temperatures, in accordance with enhanced PSs activity

Superimposed impacts of enhanced [CO2] and high temperature on the photosynthetic metabolism of C. arabica and C. canephora genotypes.

Summary: Coffee crop has been predicted to become threatened by future climate changes and global warming conditions. Yet, the long-term effects of elevated [CO2] on this plant remain to be fully elucidated. In this context, this work aims at linking coffee biochemical responses to environmental changes of [CO2] and temperature on genotypes from the two major producing species, using the photosynthetic metabolism as probe to evaluate the plant acclimation ability. Potted plants from C. arabica cv. IPR 108 and of C. canephora cv. Conilon Clone 153 were grown under environmental controlled conditions, either at 380 or 700 ?L CO2 L-1 air, for 1 year, without water, nutrient or root development restrictions. After that the temperature was gradually increased from 25/20 ºC (day/night) up to 42/34 ºC. The effects of elevated [CO2] and enhanced temperature on the photosynthetic structures were assessed through the characterization of the lipid components of chloroplast membranes, whereas the leaf metabolic performance was evaluated through the thylakoid electron transport rates (involving both photosystem (PS) I and II), and the activities of enzymes (ribulose 1,5-biphosphate carboxylase/oxygenase and ribulose 5-phosphate kinase), as well as through stable isotopes of C and N. The activities of respiratory enzymes (NADH-dependent malate dehydrogenase and pyruvate kinase) were also analyzed. The results pointed for a higher functional status along the experiment in the plants grown under elevated [CO2], with special relevance at 37 and 42ºC in IPR108. These results could be related to the qualitative changes of the membrane lipid matrix that might have helped to preserve suitable membrane fluidity for the membrane bound events (e.g., thylakoid electron transport). The PSs and enzyme data reflect an enhancement of the energetic metabolism (both photosynthesis and respiration), mostly, until 31 ºC for IPR108 and 37 ºC for CL153 at normal [CO2]. Yet, under enhanced [CO2] it was found an increase in the temperature (to 37 ºC) at which maximal values of some parameters in IPR108 (MDH, PSs activities, RuBisCO) were observed, concomitantly with the maintenance of high performance in other parameters when compared to the 380 plants. Under the highest temperature (42 ºC) the enzymes were the most sensitive point, displaying the strongest reductions, irrespective of genotype and [CO2] treatments. The temperature promoted changes in leaf ?13C, irrespective of genotype and [CO2], reflecting a decrease in WUE with heat. The changes in ?15N values may indicate different limitation steps of N assimilation, requiring further investigation. It was concluded that the coffee plants grown under elevated [CO2] apparently showed a better endurance to high temperatures, what is quite relevant in a context of predicted climate changes and global warming scenarios