Predicting dengue incidence leveraging internet-based data sources. A case study in 20 cities in Brazil

The dengue virus affects millions of people every year worldwide, causing large epidemic outbreaks that disrupt people’s lives and severely strain healthcare systems. In the absence of a reliable vaccine against dengue or an effective treatment to manage the illness in humans, most efforts to combat dengue infections have focused on preventing its vectors, mainly the Aedes aegypti mosquito, from flourishing across the world. These mosquito-control strategies need reliable disease activity surveillance systems to be deployed. Despite significant efforts to estimate dengue incidence using a variety of data sources and methods, little work has been done to understand the relative contribution of the different data sources to improved prediction. Additionally, scholarship on the topic had initially focused on prediction systems at the national- and state-levels, and much remains to be done at the finer spatial resolutions at which health policy interventions often occur. We develop a methodological framework to assess and compare dengue incidence estimates at the city level, and evaluate the performance of a collection of models on 20 different cities in Brazil. The data sources we use towards this end are weekly incidence counts from prior years (seasonal autoregressive terms), weekly-aggregated weather variables, and real-time internet search data. We find that both random forest-based models and LASSO regression-based models effectively leverage these multiple data sources to produce accurate predictions, and that while the performance between them is comparable on average, the former method produces fewer extreme outliers, and can thus be considered more robust. For real-time predictions that assume long delays (6–8 weeks) in the availability of epidemiological data, we find that real-time internet search data are the strongest predictors of dengue incidence, whereas for predictions that assume short delays (1–3 weeks), in which the error rate is halved (as measured by relative RMSE), short-term and seasonal autocorrelation are the dominant predictors. Despite the difficulties inherent to city-level prediction, our framework achieves meaningful and actionable estimates across cities with different demographic, geographic and epidemic characteristics.     

Redox imbalance induces remodeling of glucose metabolism in Rhipicephalus microplus embryonic cell line

Carbohydrate metabolism not only functions in supplying cellular energy but also has an important role in maintaining physiological homeostasis and in preventing oxidative damage caused by reactive oxygen species. Previously, we showed that arthropod embryonic cell lines have high tolerance to H₂O₂ exposure. Here, we describe that Rhipicephalus microplus tick embryonic cell line (BME26) employs an adaptive glucose metabolism mechanism that confers tolerance to hydrogen peroxide at concentrations too high for other organisms. This adaptive mechanism sustained by glucose metabolism remodeling promotes cell survival and redox balance in BME26 cell line after millimolar H₂O₂ exposure. The present work shows that this tick cell line could tolerate high H₂O₂ concentrations by initiating a carbohydrate-related adaptive response. We demonstrate that gluconeogenesis was induced as a compensation strategy that involved, among other molecules, the metabolic enzymes NADP-ICDH, G6PDH, and PEPCK. We also found that this phenomenon was coupled to glycogen accumulation and glucose uptake, supporting the pentose phosphate pathway to sustain NADPH production and leading to cell survival and proliferation. Our findings suggest that the described response is not atypical, being also observed in cancer cells, which highlights the importance of this model to all proliferative cells. We propose that these results will be useful in generating basic biological information to support the development of new strategies for disease treatment and parasite control.     

HHV-6 infection in Italy: characterization of an endemic isolate and seroepidemiologic analysis

A biologic, immunologic and molecular characterization of an HHV-6 isolate (BA92) rescued by the peripheral blood mononuclear cells of a child affected by Exanthem subitum is reported. The comparison with the known HHV-6 prototype strains showed that BA92 is indistinguishable from the Z29 isolate, and can be included in the variant B group of HHV-6. A seroepidemiologic analysis of the antibody response to BA92 of normal individuals as well as patients affected by diseases potentially associated to HHV-6 infection has shown an overall seroprevalence of 81%, and that no variations in seroprevalence or in antibody geometric mean titer are observed assaying the sera also against G.S., U1102, or Z29 infected cells, respectively. These findings indicate: (1) HHV-6 infection is widely diffuse in Italy; (2) it is not possible to discriminate between the viral variants by the currently available IF assays, and (3) no conclusions can be drawn on the potential association of HHV-6 with any of the diseases examined.     

Italian Development Cooperation: the commitment for the struggle against malaria in Africa

The Italian Development Cooperation (DGCS) support the health reform process in Developing Countries, with the aim to provide populations in greatest need with access to decentralized health services. DGCS acts in close coordination with the donor community, United Nations' system and the World Bank, in agreement with sector-wide approach (SWAP) for health sector development. Since malaria control in endemic countries is a relevant component of the health system, DGCS is actively involved in the struggle against malaria in sub-Saharan Africa, supporting control activities and research capability strengthening. The following African countries are presently receiving bilateral support for antimalaria activities: Burkina Faso, Centre de Lutte contre le Paludisme in Ouagadougou; Ethiopia, community-based malaria control in Tigray; Eritrea, malaria control at national level in the framework of the Public Health and Rehabilitation Programme for Eritrea (PHARPE) initiative; Madagascar, malaria surveillance at national level; Tanzania, feasibility study for the support to the national malaria control programme. Support is provided by technical/financial assistance involving Italian academic and research institutions. On the multilateral channel, DGCS has provided regular contribution for WHO's work in malaria control and participates to the WHO Roll Back Malaria initiative. A new commitment to malaria is the trilateral joint scientific endeavour USA-Italy-Burkina Faso for the development and field testing of a candidate vaccine suitable for African populations.     

Is there an Asian bioethics?

Japan and China have long resisted the Western trend of organ transplantation from brain-dead patients, based on a 'Confucian' respect for integrity of ancestors' bodies. While their general publics continue to harbor grave doubts about such practices, their medical and political elites are hastening towards the road of organ-harvesting and organ-marketing, largely for economic reasons. This report illustrates the ways that economics is motivating brain-death legislation in Japan and criminal executions in China.     

Aluminum Enhances Melanin-Induced Lipid Peroxidation

The present study was conducted to characterize the possible interaction of Al³⁺ and Fe²⁺ with synthetic melanin in the potentiation of lipid peroxidation in liposomes and rat caudate-putamen homogenates. Al³⁺ stimulated melanin-initiated lipid peroxidation as measured by the production of 2-thiobarbituric acid-reactive substances (TBARS) and conjugated dienes. The effect of Al³⁺ was dependent on melanin (10–100 g/ml) and Al³⁺ (2.5–250 M) concentrations and no synergism between Fe²⁺ and Al³⁺ was observed. The prooxidant effect of Al³⁺ was partially inhibited by superoxide dismutase indicating the involvement of O ₂ ^- . Ga³⁺ and Be²⁺ which can increase NADH oxidation in the presence of O ₂ ^- , also were shown to stimulate melanin-initiated TBARS production. Based on the effect of Al³⁺ and other non redox metals, we suggest that Al³⁺ does not act through either the induction of melanin free radicals, or the induction of changes in membrane physical properties. Results show that Al³⁺ enhances melanin-initiated lipid peroxidation in part through an interaction with O ₂ ^- generated from the autoxidation of melanin. We speculate that Al³⁺ contributes to neuromelanin-mediated oxidative damage in dopaminergic neurons and subsequent neuronal degeneration and death in Parkinson's disease.     

Floral nectaries, nectar production dynamics and chemical composition in six ipomoea species (convolvulaceae) in relation to pollinators

BACKGROUND AND AIMS: Floral nectaries and nectar features were compared between six Argentinian Ipomoea species with differences in their pollinator guilds: I. alba, I. rubriflora, I. cairica, I. hieronymi var. hieronymi, I. indica, and I. purpurea. METHODS: Pollinators were recorded in natural populations. The morpho-anatomical study was carried out through scanning electron and light microscopy. Nectar sugars were identified via gas chromatography. Nectar production and the effect of its removal on total nectar sugar amount were determined by using sets of bagged flowers. KEY RESULTS: Hymenopterans were visitors of most species, while hummingbirds visited I. rubriflora and sphingids I. alba. All the species had a vascularized discoidal nectary surrounding the ovary base with numerous open stomata with a species-specific distribution. All nectar samples contained amino acids and sugars. Most species had sucrose-dominant nectars. Flowers lasted a few hours. Mean nectar sugar concentration throughout the lifetime of the flower ranged from 34.28 to 39.42 %, except for I. cairica (49.25 %) and I. rubriflora (25.18 %). Ipomoea alba had the highest nectar volume secreted per flower (50.12 microL), while in the other taxa it ranged from 2.42 to 12.00 microL. Nectar secretion began as soon as the flowers opened and lasted for a few hours (in I. purpurea, I. rubriflora) or it was continuous during the lifetime of the flower (in the remaining species). There was an increase of total sugar production after removals in I. cairica, I. indica and I. purpurea, whereas in I. alba and I. rubriflora removals had no effect, and in I. hieronymi there was a decrease in total sugar production. CONCLUSIONS: The chemical composition, production dynamics and removal effects of nectar could not be related to the pollinator guild of these species. Flower length was correlated with nectary size and total volume of nectar secreted, suggesting that structural constraints may play a major role in the determination of nectar traits of these species.     

Information encoding in the inferior temporal visual cortex: contributions of the firing rates and the correlations between the firing of neurons

The encoding of information by populations of neurons in the macaque inferior temporal cortex was analyzed using quantitative information-theoretic approaches. It was shown that almost all the information about which of 20 stimuli had been shown in a visual fixation task was present in the number of spikes emitted by each neuron, with stimulus-dependent cross-correlation effects adding for most sets of simultaneously recorded neurons almost no additional information. It was also found that the redundancy between the simultaneously recorded neurons was low, approximately 4% to 10%. Consistent with this, a decoding procedure applied to a population of neurons showed that the information increases approximately linearly with the number of cells in the population. AcknowledgementsThis research was supported by the Medical Research Council, grant PG9826105, by the Human Frontier Science Program, by the MRC Interdisciplinary Research Centre for Cognitive Neuroscience, and by the Wellcome Trust.     

A touching sight: SII/PV activation during the observation and experience of touch

Watching the movie scene in which a tarantula crawls on James Bond's chest can make us literally shiver--as if the spider crawled on our own chest. What neural mechanisms are responsible for this "tactile empathy"? The observation of the actions of others activates the premotor cortex normally involved in the execution of the same actions. If a similar mechanism applies to the sight of touch, movies depicting touch should automatically activate the somatosensory cortex of the observer. Here we found using fMRI that the secondary but not the primary somatosensory cortex is activated both when the participants were touched and when they observed someone or something else getting touched by objects. The neural mechanisms enabling our own sensation of touch may therefore be a window also to our understanding of touch.