Prospective study of patients with persistent symptoms of dengue in Brazil

Dengue is an arboviral infection clinically recognized as an acute and self-limited disease. Persistence of dengue symptoms is known, but it has been little studied. The aim of this study was to characterize persistent symptoms in 113 patients with dengue followed up clinically and by laboratory testing at a tertiary hospital. Symptoms that persisted for more than 14 days were observed in 61 (54.0%) patients, and six (6.2%) of them had symptoms for 6 months or more. The persistent symptoms identified were myalgia, weakness, hair loss, memory loss, reduced resistance to physical effort, headache, reasoning problems, arthralgia, sleepiness- and emotional lability. The progression to persistent symptoms was significantly associated with hospitalization, older age, more severe disease, the presence of bleeding and comorbidities upon univariate analysis. Upon multivariate analysis, the presence of persistent symptoms continued to be significantly associated only with increased age and dengue with warning signs. The platelet count during the acute phase of the disease was significantly lower in the group with persistent symptoms. In conclusion, the frequency of progression to persistent symptoms in dengue is relevant in patients seen at a tertiary hospital and the persistence of symptoms is more common in patients with dengue with warning signs

Activity patterns of free-ranging koalas (Phascolarctos cinereus) revealed by accelerometry

An understanding of koala activity patterns is important for measuring the behavioral response of this species to environmental change, but to date has been limited by the logistical challenges of traditional field methodologies. We addressed this knowledge gap by using tri-axial accelerometer data loggers attached to VHF radio collars to examine activity patterns of adult male and female koalas in a high-density population at Cape Otway, Victoria, Australia. Data were obtained from 27 adult koalas over two 7-d periods during the breeding season: 12 in the early-breeding season in November 2010, and 15 in the late-breeding season in January 2011. Multiple 15 minute observation blocks on each animal were used for validation of activity patterns determined from the accelerometer data loggers. Accelerometry was effective in distinguishing between inactive (sleeping, resting) and active (grooming, feeding and moving) behaviors. Koalas were more active during the early-breeding season with a higher index of movement (overall dynamic body acceleration [ODBA]) for both males and females. Koalas showed a distinct temporal pattern of behavior, with most activity occurring from mid-afternoon to early morning. Accelerometry has potential for examining fine-scale behavior of a wide range of arboreal and terrestrial species

From Sensor Data to Animal Behaviour: An Oystercatcher Example

Animal-borne sensors enable researchers to remotely track animals, their physiological state and body movements. Accelerometers, for example, have been used in several studies to measure body movement, posture, and energy expenditure, although predominantly in marine animals. In many studies, behaviour is often inferred from expert interpretation of sensor data and not validated with direct observations of the animal. The aim of this study was to derive models that could be used to classify oystercatcher (Haematopus ostralegus) behaviour based on sensor data. We measured the location, speed, and tri-axial acceleration of three oystercatchers using a flexible GPS tracking system and conducted simultaneous visual observations of the behaviour of these birds in their natural environment. We then used these data to develop three supervised classification trees of behaviour and finally applied one of the models to calculate time-activity budgets. The model based on accelerometer data developed to classify three behaviours (fly, terrestrial locomotion, and no movement) was much more accurate (cross-validation error = 0.14) than the model based on GPS-speed alone (cross-validation error = 0.35). The most parsimonious acceleration model designed to classify eight behaviours could distinguish five: fly, forage, body care, stand, and sit (cross-validation error = 0.28); other behaviours that were observed, such as aggression or handling of prey, could not be distinguished. Model limitations and potential improvements are discussed. The workflow design presented in this study can facilitate model development, be adapted to a wide range of species, and together with the appropriate measurements, can foster the study of behaviour and habitat use of free living animals throughout their annual routine

Serotype influences on dengue severity: a cross-sectional study on 485 confirmed dengue cases in Vitória, Brazil

Abstract Background Dengue is caused by a RNA virus of the family Flaviviridae, which presents four serotypes (DENV-1 to DENV-4) capable of inducing hemorrhage. The purpose of this study was to evaluate the influence of serotype on the outcome of dengue. Methods This cross-sectional study included data from dengue cases with serotyping results that occurred between 2009 and 2013 in Vitória, Espírito Santo, Brazil. Data were accessed through the Information System for Notifiable Diseases. Chi-square test, Fisher exact test, Mann–Whitney U test, and logistic regression were performed to assess associations between different serotypes and dengue severity, while considering gender and age. Results The sample consisted of 485 laboratory confirmed dengue cases, of which 46.4 % were females, with median age of 26 years. Regarding overall samples, 77.3 % were caused by DENV-1, 16.1 % by DENV-4, 6.4 % by DENV-2, and 0.2 % by DENV-3. Severe dengue affected 6.6 % of all cases, of which 32.3 % of the cases caused by DENV-2, 6.4 % of those caused by DENV-4, 4.5 % of those caused by DENV-1, and none of those caused by DENV-3. Severe dengue was found to be seven times more frequent among cases of DENV-2 than among those of the other serotypes. Conclusions The present study found that cases of DENV-2 had a higher proportion of severe dengue than among those of DENV-1 and DENV-4. Consequently, early detection of serotypes circulating in the territory could be an important approach to prevent increasing numbers of severe outcomes during dengue outbreaks by predicting the health support needed for early diagnoses and treatment of dengue cases

The North Atlantic Aerosol and Marine Ecosystem Study (NAAMES): Science Motive and Mission Overview

The North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) is an interdisciplinary investigation to improve understanding of Earth's ocean ecosystem-aerosol-cloud system. Specific overarching science objectives for NAAMES are to (1) characterize plankton ecosystem properties during primary phases of the annual cycle and their dependence on environmental forcings, (2) determine how these phases interact to recreate each year the conditions for an annual plankton bloom, and (3) resolve how remote marine aerosols and boundary layer clouds are influenced by plankton ecosystems. Four NAAMES field campaigns were conducted in the western subarctic Atlantic between November 2015 and April 2018, with each campaign targeting specific seasonal events in the annual plankton cycle. A broad diversity of measurements were collected during each campaign, including ship, aircraft, autonomous float and drifter, and satellite observations. Here, we present an overview of NAAMES science motives, experimental design, and measurements. We then briefly describe conditions and accomplishments during each of the four field campaigns and provide information on how to access NAAMES data. The intent of this manuscript is to familiarize the broad scientific community with NAAMES and to provide a common reference overview of the project for upcoming publications

The North Atlantic Aerosol and Marine Ecosystem Study (NAAMES): Science Motive and Mission Overview

The North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) is an interdisciplinary investigation to improve understanding of Earth's ocean ecosystem-aerosol-cloud system. Specific overarching science objectives for NAAMES are to (1) characterize plankton ecosystem properties during primary phases of the annual cycle and their dependence on environmental forcings, (2) determine how these phases interact to recreate each year the conditions for an annual plankton bloom, and (3) resolve how remote marine aerosols and boundary layer clouds are influenced by plankton ecosystems. Four NAAMES field campaigns were conducted in the western subarctic Atlantic between November 2015 and April 2018, with each campaign targeting specific seasonal events in the annual plankton cycle. A broad diversity of measurements were collected during each campaign, including ship, aircraft, autonomous float and drifter, and satellite observations. Here, we present an overview of NAAMES science motives, experimental design, and measurements. We then briefly describe conditions and accomplishments during each of the four field campaigns and provide information on how to access NAAMES data. The intent of this manuscript is to familiarize the broad scientific community with NAAMES and to provide a common reference overview of the project for upcoming publications