The Importance of Spatiotemporal Fish Population Dynamics in Barrier Mitigation Planning

In this study, we propose a novel framework combining spatially explicit population viability analysis and optimization for prioritizing fish passage barrier mitigation decisions. Our model aims to maximize the equilibrium population size, or alternatively minimize the extinction risk, of a target fish species subject to a budget on the total cost of barrier mitigation. A case study involving a wild coho salmon (Oncorhynchus kisutch) population from the Tillamook basin, Oregon, USA is used to illustrate the benefits of our approach. We consider two different spawning adult dispersal patterns, river and reach level homing, as well as straying. Under density dependent population growth, we find that homing behavior type has a significant effect on barrier mitigation decisions. In particular, with reach homing, our model produces virtually the same population sizes as a more traditional barrier prioritization procedure designed to maximize accessible habitat. With river homing, however, we find that it is not necessary to remove all barriers in order to maximize equilibrium population size. Indeed, a stochastic version of our model reveals that removing all barriers actually results in a marginal increase in quasi-extinction risk. We hypothesize that this is due to a population thinning effect of barriers, resulting in a surplus of recruits in areas of low spawner density. Our findings highlights the importance of considering spatiotemporal fish population dynamics in river connectivity restoration planning. By adding greater biological realism, models such as ours can help conservation managers to more strategically allocate limited resources, resulting in both cost savings and improved population status for a focal species

Optimising river infrastructure placement and mitigation decisions

We address the problem of locating small hydropower dams in an environmentally friendly manner. We propose the use of a multi-objective optimization model to maximize total hydropower production, while limiting negative impacts on river connectivity. Critically, we consider the so called "backwater effects" that dams have on power generation at nearby upstream sites via changes in water surface profiles. We further account for the likelihood that migratory fish and other aquatic species can successfully pass hydropower dams and other artificial/natural barriers and how this is influenced by backwater effects. Although naturally represented in nonlinear form, we manage through a series of linearization steps to formulate a mixed integer linear programing model. We illustrate the utility of our proposed framework using a case study from England and Wales. Interestingly, we show that for England and Wales, a region heavily impacted by a large number of existing river barriers, installation of small hydropower dams fitted with even moderately effective fish passes can, in fact, create a win-win situation that results in increased hydropower and improved river connectivity. We also propose a novel optimization framework to prioritize fish passage barrier mitigation decisions that incorporates both fish population and dispersal dynamics in order to maximize equilibrium population size. A case study involving a wild coho salmon (Oncorhynchus kisutch) population from the Tillamook basin, Oregon, USA is used to illustrate the benefits of our approach. We consider two extreme homing patterns, river and reach level homing, as well as straying. Under density dependent population growth, we find that the type of homing behavior has a significant effect on barrier mitigation decisions. In particular, with reach homing, our model results in virtually the same population sizes as a more traditional barrier prioritization procedure that seeks to maximize the accessible habitat. With river homing, however, there is no need to remove all barriers to maximize equilibrium population size. Indeed, a stochastic version of our model reveals that removing all barriers actually results in a marginal increase in quasi-extinction risk. We hypothesize that this is due to a population thinning effect of barriers, resulting in a surplus of recruits in areas of low spawner density. Our present study should prove useful to fish conservation managers by assessing the relative importance of incorporating spatiotemporal fish population dynamics in river connectivity restoration planning. Finally, habitat fragmentation is a leading threat to global biodiversity. Restoring habitat connectivity, especially in freshwater systems, is considered essential in improving ecosystem function and health. Various studies have looked at cost effectively prioritizing river barrier mitigation decisions. In none of these, however, has the importance of accounting for the potential presence of unknown or "hidden" barriers been considered. In this study, we propose a novel optimization based approach that accounts for hidden barrier uncertainty in river connectivity restoration planning and apply it in a case study of the US state of Maine. We find that ignoring hidden barriers leads to a dramatic reduction in anticipated accessible habitat gains. Using a conventional prioritization approach, habitat gains are on average 60% lower than expected across a range of budgets when there are just 10% additional but unknown barriers. More importantly our results show that anticipating for hidden barriers can improve potential gains in accessible habitat in excess of 110% when the budget is low and the number of hidden barriers comparatively large. Finally, we find that solutions optimized for an intermediate number of unknown barriers perform well regardless of the actual number of hidden barriers. In other words, we can build-in robustness into the barrier removal planning framework. Dealing with the hidden elephant in the room could lead to a far more realistic approach of the habitat connectivity restoration issue

Building and evaluating resources for sentiment analysis in the Greek language

Sentiment lexicons and word embeddings constitute well-established sources of information for sentiment analysis in online social media. Although their effectiveness has been demonstrated in state-of-the-art sentiment analysis and related tasks in the English language, such publicly available resources are much less developed and evaluated for the Greek language. In this paper, we tackle the problems arising when analyzing text in such an under-resourced language. We present and make publicly available a rich set of such resources, ranging from a manually annotated lexicon, to semi-supervised word embedding vectors and annotated datasets for different tasks. Our experiments using different algorithms and parameters on our resources show promising results over standard baselines; on average, we achieve a 24.9% relative improvement in F-score on the cross-domain sentiment analysis task when training the same algorithms with our resources, compared to training them on more traditional feature sources, such as n-grams. Importantly, while our resources were built with the primary focus on the cross-domain sentiment analysis task, they also show promising results in related tasks, such as emotion analysis and sarcasm detection

Active surveillance of Q fever in human and animal population of Cyprus

BACKGROUND: A long-term active surveillance of Q fever was conducted in Cyprus organized in two phases. METHODS: Following serological tests and identification of seropositive humans and animals for C. burnetii in two villages (VIL1 and VIL2), all seronegative individuals were followed up for one year on a monthly basis by trained physicians to detect possible seroconversion for Q fever. In the second phase of the study, active surveillance for one year was conducted in the entire Cyprus. Physicians were following specific case definition criteria for Q fever. Standardized questionnaires, a geographical information system on a regional level, Immunofluorescence Assay (IFA) examinations and shell vial technique were used. RESULTS: Eighty-one seronegative humans and 239 seronegative animals from both villages participated in the first phase surveillance period of Q fever. Despite the small number of confirmed clinical cases (2 humans and 1 goat), a significant percentage of new seropositives for C. burnetii (44.4% of human participants and 13.8% of animals) was detected at the end of the year. During the second phase of surveillance, 82 humans, 100 goats, and 76 sheep were considered suspected cases of Q fever. However, only 9 human, 8 goat, and 4 sheep cases were serologically confirmed, while C. burnetii was isolated from three human and two animal samples. The human incidence rate was estimated at 1.2 per 100,000 population per year. CONCLUSION: A small number of confirmed clinical cases of Q fever were observed despite the high seroprevalence for C. burnetii in human and animal population of Cyprus. Most of the cases in the local population of Cyprus appear to be subclinical. Moreover further studies should investigate the role of ticks in the epidemiology of Q fever and their relation to human seropositivity

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Modulation des processus comportementaux par le système endocannabinoïde : de l'adolescence à l'âge adulte

The endocannabinoid system (ECS) is a crucial modulatory system involved in the regulation of diverse brain functions and behavior. The ECS is the target of the main psychoactive component of cannabis, Δ9-tetrahydrocannabinol (THC), which exerts many of its psychotomimetic effects by binding to brain cannabinoid type-1 (CB1) receptors. Cannabis is currently the most widely used psychoactive substance worldwide, with the highest consumption rate observed among adolescents and young adults. Adolescence comprises a sensitive developmental period, during which cannabinoid drugs can easily disrupt the normative trajectory of brain maturation, giving rise to long-term consequences. Indeed, the association between adolescent cannabis use and persistent negative outcomes has long been the focus of neuroscience research, with numerous studies associating these outcomes with a range of neuropsychiatric disorders—psychotic disorders being some the most prominent. However, the mechanisms linking cannabinoid exposure to long-term behavioral effects are complex, and results in the field remain inconclusive. Animal models exposed to THC during developmental periods (e.g, adolescence) are therefore critical to assess the impact of cannabis use. By using a model of adolescent THC in mice, the first aim of this study was to characterize the specific adult behavioral profile of male and female mice. To this end, a set of psychotic-like behavioral processes related to motor, social and cognitive functions were evaluated in adulthood. Moreover, in order to assess possible alterations in mental sensory representations, which more accurately represent the distinctive features of the core psychotic symptoms (i.e. hallucinations and delusions), we investigated the effect of adolescent THC in a representation-mediated learning protocol. Resembling cannabis-induced psychotic states in humans, impairments in this protocol have been described after acute administration of THC, however the effect of adolescent THC has never been investigated. Altogether, our findings reveal sex-dependent effects, with adolescent THC mainly disrupting motor, social, and short-term memory functions in male mice, and associative learning and memory in female mice. The second aim of this study was to explore potential neurobiological mechanisms underlying the effects of adolescent THC. Therefore, we performed analysis of the CB1 receptor status and signaling targets (such as the ERK and CREB proteins), observing sex- and region-dependent changes. Our recent findings have shown that mitochondrial Complex I (CI) instability through the specific de-phosphorylation of its NDUFS4 subunit in astrocytes is the mechanism leading to persistent THC-induced social deficits. Here, we demonstrated that NDUFS4 phosphorylation is specifically decreased by adolescent THC in male, but not in female mice, suggesting that the phosphorylation status of this CI subunit might be responsible for the sex-specific behavioral effects. Notably, astroglial expression of a phosphomimetic mutant form of NDUFS4 was able to prevent the adolescent THC-induced behavioral effects on locomotion and social interaction in adult male mice. These results strongly support the idea that mitochondrial alterations in astrocytes are causally involved in the enduring behavioral effects of adolescent THC, highlighting the emerging role of cellular bioenergetics in the regulation of behavior.Le système endocannabinoïde (SEC) est un système modulateur impliqué dans la régulation de fonctions cérébrales et processus comportementaux. Le SEC est la cible du principal composant psychoactif du cannabis, le Δ9-tétrahydrocannabinol (THC), qui exerce la plupart de ses effets psychotomimétiques en se liant aux récepteurs cannabinoïdes de type 1 (CB1) du cerveau. Le cannabis est le psychotrope le plus largement utilisé dans le monde, les adolescents et les jeunes adultes ayant le taux de consommation le plus élevé. L'adolescence est une période sensible du développement, au cours de laquelle le cannabis peut facilement affecter la maturation du cerveau, entraînant des conséquences à long terme. L'association entre la consommation de cannabis à l'adolescence et des effets négatifs persistants est depuis longtemps étudiée en neurosciences, des études identifiant une série de troubles neuropsychiques - les troubles psychotiques étant parmi les plus fréquents. Cependant, les mécanismes reliant l'exposition aux cannabinoïdes aux effets comportementaux à long terme sont complexes, et les études dans ce domaine restent peu concluantes. Les modèles précliniques où les animaux sont exposés au THC pendant les périodes de développement (dont l'adolescence) sont essentiels pour évaluer l'impact de la consommation de cannabis. En utilisant un modèle d’exposition au THC à l’adolescence chez la souris, le premier objectif de ma thèse était de caractériser le profil comportemental à l’âge adulte de souris mâles et femelles. Dans ce but, une batterie de tests comportementaux a été réalisée à l’âge adulte permettant d’étudier une possible altération des fonctions motrices, sociales et cognitives. De plus, afin d'évaluer les altérations possibles des représentations sensorielles mentales, caractéristiques majeures des symptômes psychotiques (i.e. hallucinations et délires), nous avons étudié l'effet de l’exposition au THC à l’adolescence dans un protocole d'apprentissage associatif d'ordre supérieur, i.e. reposant sur les représentations sensorielles internes. Nos résultats révèlent des effets dépendants du sexe, l’exposition au THC à l’adolescence perturbant les fonctions motrices, sociales et de mémoire à court terme chez les souris mâles, et l'apprentissage et la mémoire associative chez les souris femelles. Le deuxième objectif de cette étude était d'explorer les mécanismes neurobiologiques potentiels qui sous-tendent les effets de l’exposition au THC à l’adolescence. Nous avons analysé le niveau d’expression des récepteurs CB1 et ses voies de signalisation, et nous avons observé des changements dépendants du sexe et de la région. Nos études récentes ont révélé que l'instabilité du complexe I (CI) mitochondrial par déphosphorylation spécifique de sa sous-unité NDUFS4 dans les astrocytes constitue le mécanisme conduisant aux déficits sociaux à long terme induits par le THC. Au cours de ma thèse, nous avons démontré que la phosphorylation de NDUFS4 est diminuée par l’exposition au THC à l'adolescence chez les souris mâles, mais pas chez les souris femelles, suggérant que le statut de phosphorylation de cette sous-unité du CI pourrait être responsable des effets comportementaux dépendant du sexe. En particulier, l’expression d’une forme active de NDUFS4 dans les astrocytes a prévenu les effets de l’exposition au THC à l’adolescence sur la locomotion et les interactions sociales évaluées chez la souris mâle adulte. Ces résultats soutiennent donc l'idée que des altérations mitochondriales au sein des astrocytes seraient impliquées dans les effets comportementaux à long terme de l’exposition au THC à l’adolescence, soulignant le rôle de la bioénergétique cellulaire dans la régulation comportementale