The Firefighter Problem: A Structural Analysis

We consider the complexity of the firefighter problem where b>=1 firefighters are available at each time step. This problem is proved NP-complete even on trees of degree at most three and budget one (Finbow et al.,2007) and on trees of bounded degree b+3 for any fixed budget b>=2 (Bazgan et al.,2012). In this paper, we provide further insight into the complexity landscape of the problem by showing that the pathwidth and the maximum degree of the input graph govern its complexity. More precisely, we first prove that the problem is NP-complete even on trees of pathwidth at most three for any fixed budget b>=1. We then show that the problem turns out to be fixed parameter-tractable with respect to the combined parameter "pathwidth" and "maximum degree" of the input graph

Trade-offs during the COVID-19 pandemic: A discrete choice experiment about policy preferences in Portugal

The need to control the sanitary situation during the COVID-19 pandemic has led governments to implement several restrictions with substantial social and economic impacts. We explored people’s trade-offs in terms of their income, life restrictions, education, and poverty in the society, compared to their willingness to avoid deaths. We applied a web-based discrete choice experiment to elicit preferences of the Portuguese citizens for these attributes and computed the marginal rate of substitution in terms of avoided deaths. We recorded 2,191 responses that faced the possibility of having 250 COVID-19 related deaths per day as the worst possible outcome from the choice levels presented. Estimates suggested that individuals would be willing to sacrifice 30% instead of 10% of their income to avoid approximately 47 deaths per day during the first six months of 2021. For the same period, they would also accept 30% of the students’ population to become educationally impaired, instead of 10%, to avoid approximately 25 deaths; a strict lockdown, instead of mild life restrictions, to avoid approximately 24 deaths; and 45% of the population to be in risk of poverty, instead of 25%, to avoid approximately 101 deaths. Our paper shows that avoiding deaths was strongly preferred to the remaining societal impacts; and that being a female, as well as working on site, led individuals to be more averse to such health hazards. Furthermore, we show how a DCE can be used to assess the societal support to decision-making during times of crisis

The cyclic interaction between daytime behavior and the sleep behavior of laboratory dogs

Sleep deprivation has been found to negatively affect an individual´s physical and psychological health. Sleep loss affects activity patterns, increases anxiety-like behaviors, decreases cognitive performance and is associated with depressive states. The activity/rest cycle of dogs has been investigated before, but little is known about the effects of sleep loss on the behavior of the species. Dogs are polyphasic sleepers, meaning the behavior is most observed at night, but bouts are also present during the day. However, sleep can vary with ecological and biological factors, such as age, sex, fitness, and even human presence. In this study, kennelled laboratory adult dogs’ sleep and diurnal behavior were recorded during 24-h, five-day assessment periods to investigate sleep quality and its effect on daily behavior. In total, 1560 h of data were analyzed, and sleep metrics and diurnal behavior were quantified. The relationship between sleeping patterns and behavior and the effect of age and sex were evaluated using non-parametric statistical tests and GLMM modelling. Dogs in our study slept substantially less than previously reported and presented a modified sleep architecture with fewer awakenings during the night and almost no sleep during the day. Sleep loss increased inactivity, decreased play and alert behaviors, while increased time spent eating during the day. Males appeared to be more affected by sleep fragmentation than females. Different age groups also experienced different effects of sleep loss. Overall, dogs appear to compensate for the lack of sleep during the night by remaining inactive during the day. With further investigations, the relationship between sleep loss and behavior has the potential to be used as a measure of animal welfare

Amazonian trees have limited capacity to acclimate plant hydraulic properties in response to long‐term drought

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordThe fate of tropical forests under future climate change is dependent on the capacity of their trees to adjust to drier conditions. The capacity of trees to withstand drought is likely to be determined by traits associated with their hydraulic systems. However, data on whether tropical trees can adjust hydraulic traits when experiencing drought remain rare. We measured plant hydraulic traits (e.g. hydraulic conductivity and embolism resistance) and plant hydraulic system status (e.g. leaf water potential, native embolism and safety margin) on >150 trees from 12 genera (36 species) and spanning a stem size range from 14 to 68 cm diameter at breast height (DBH) at the world's only long‐running tropical forest drought experiment. Hydraulic traits showed no adjustment following 15 years of experimentally imposed moisture deficit. This failure to adjust resulted in these drought‐stressed trees experiencing significantly lower leaf water potentials, and higher, but variable, levels of native embolism in the branches. This result suggests that hydraulic damage caused by elevated levels of embolism is likely to be one of the key drivers of drought‐induced mortality following long‐term soil moisture deficit. We demonstrate that some hydraulic traits changed with tree size, however, the direction and magnitude of the change was controlled by taxonomic identity. Our results suggest that Amazonian trees, both small and large, have limited capacity to acclimate their hydraulic systems to future droughts, potentially making them more at risk of drought‐induced mortality.Natural Environment Research Council (NERC)Brazilian Higher Education Coordination Agency (CAPES)Royal SocietyEuropean Union FP7ARCFAPESP/Microsof

Physical activity level in people with high blood pressure

This study aimed to analyze the level of physical activity for people with high blood pressure cared for in a health center. This cross-sectional study was conducted with 310 individuals between 18 and 69 years of age through the International Physical Activity Questionnaire (IPAQ). The majority (80%) of participants presented low or moderate levels of physical activity. The analysis of association between sociodemographic variables and physical activity level revealed that older men from the interior of the state with higher educational levels have a greater chance of exhibiting lower levels of physical activity. The logistic regression model revealed that origin, schooling and diabetes are predictors of low physical activity level. The conclusion is that part of the sample does not match the desirable profile to practice regular physical activity.El objetivo de este estudio fue analizar el nivel de actividad física de personas portadoras de hipertensión arterial, acompañadas en un centro de atención ambulatorial. Se trata de un estudio transversal desarrollado con 310 individuos de 18 a 69 años. Se utilizó como base el International Physical Activity Questionnaire (IPAQ). La mayor parte del grupo (80%) fue encuadrada en los niveles de baja y moderada actividad física. En el análisis de asociación entre las variables sociodemográficas y el nivel de actividad física, se verificó que personas del sexo masculino, procedentes del interior del Estado, con más edad y con mayor nivel de escolaridad son más propensas a desarrollar un nivel de actividad física bajo. En el modelo de regresión logística, la procedencia, tiempo de escolaridad y de diabetes fueron indicadores obtenidos como factores de predicción significativos para el nivel bajo de actividad física. Se concluye que parte de la muestra no posee un perfil deseable en relación a la práctica regular de actividad física.O objetivo desse estudo foi analisar o nível de atividade física de pessoas portadoras de hipertensão arterial, acompanhadas em centro de atendimento ambulatorial. É um estudo transversal desenvolvido com 310 indivíduos de 18 a 69 anos. Utilizou-se como base o International Physical Activity Questionnaire (IPAQ). A maior parcela do grupo (80%) foi enquadrada nos níveis de baixa e moderada atividade física. Na análise de associação entre as variáveis sociodemográficas e o nível de atividade física, verificou-se que pessoas do sexo masculino, procedentes do interior do Estado, mais velhas e com maior nível de escolaridade são mais propensas para desenvolver nível de atividade física baixo. No modelo de regressão logística, a procedência, tempo de escolaridade e de diabetes foram indicadores obtidos como preditores significantes para o nível baixo de atividade física. Concluiu-se que parte da amostra não possui perfil desejável em relação à prática regular de atividade física

Genotyping of two Neisseria gonorrhoeae fluroquinolone-resistant strains in the Brazilian Amazon Region

We report two ciprofloxacin and ofloxacin-resistant Neisseria gonorrhoeae strains that were isolated from the urethral discharge of male patients at the sexually transmitted diseases outpatient clinic of the Alfredo da Matta Foundation (Manaus, state of Amazonas, Brazil). The gonococci displayed minimal inhibitory concentrations (> 32.00 µg/mL) and three mutations in the quinolone resistance-determining region (S91F and D95G in GyrA and S87R in ParC). Both isolates were genotyped using N. gonorrhoeae multi-antigen sequence typing and the analysis showed that the ST225 which represented an emerging widespread multi-resistant clone that has also been associated with reduced susceptibility to ceftriaxone. We recommend continued surveillance of this pathogen to assess the efficacy of anti-gonococcal antibiotics in Brazil