Effects of temperature and photoperiod on daily activity rhythms of Lutzomyia longipalpis (Diptera: Psychodidae)

Made available in DSpace on 2015-05-04T17:07:27Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) gustavo_rivasetal_IOC_2014.pdf: 728382 bytes, checksum: f0dd4d5e2dd3f6987745ff64d4383f08 (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Flavivírus. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Leishmanioses. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Flavivírus. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM)/CNPq. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Flavivírus. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM)/CNPq. Rio de Janeiro, RJ, Brasil.Background: Insect vectors have been established as models in Chronobiology for many decades, and recent studies have demonstrated a close relationship between the circadian clock machinery, daily rhythms of activity and vectorial capacity. Lutzomyia longipalpis, the primary vector of Leishmania (Leishmania) infantum in the New World, is reported to have crepuscular/nocturnal activity in the wild. However, most of these studies applied hourly CDC trap captures, which is a good indicative of L. longipalpis behaviour, but has limited accuracy due to the inability to record the daily activity of a single insect during consecutive days. In addition, very little is known about the activity pattern of L. longipalpis under seasonal variations of average temperature and day length in controlled laboratory conditions. Methods: We recorded the locomotor activity of L. longipalpis males under different artificial regimes of temperature and photoperiod. First, in order to test the effects of temperature on the activity, sandflies were submitted to regimes of light/dark cycles similar to the equinox photoperiod (LD 12:12) combined with different constant temperatures (20°C, 25°C and 30°C). In addition, we recorded sandfly locomotor activity under a mild constant temperature (25°C with different day length regimes: 8 hours, 12 hours and 16 hours). Results: L. longipalpis exhibited more activity at night, initiating dusk-related activity (onset time) at higher rather than lower temperatures. In parallel, changes of photoperiod affected anticipation as well as all the patterns of activity (onset, peak and offset time). However, under LD 16:08, sandflies presented the earliest values of maximum peak and offset times, contrary to other regimes. Conclusions: Herein, we showed that light and temperature modulate L. longipalpis behaviour under controlled laboratory conditions, suggesting that sandflies might use environmental information to sustain their crepuscular/ nocturnal activity, as well as other important aspects as mating and host-seeking at appropriate times in different seasons. Our results depict previously unappreciated aspects of the L. longipalpis daily rhythms of activity that might have important epidemiological implications

Multiphase modelling of tumour growth and extracellular matrix interaction: mathematical tools and applications

Resorting to a multiphase modelling framework, tumours are described here as a mixture of tumour and host cells within a porous structure constituted by a remodelling extracellular matrix (ECM), which is wet by a physiological extracellular fluid. The model presented in this article focuses mainly on the description of mechanical interactions of the growing tumour with the host tissue, their influence on tumour growth, and the attachment/detachment mechanisms between cells and ECM. Starting from some recent experimental evidences, we propose to describe the interaction forces involving the extracellular matrix via some concepts coming from viscoplasticity. We then apply the model to the description of the growth of tumour cords and the formation of fibrosis

A Viral Dynamic Model for Treatment Regimens with Direct-acting Antivirals for Chronic Hepatitis C Infection

We propose an integrative, mechanistic model that integrates in vitro virology data, pharmacokinetics, and viral response to a combination regimen of a direct-acting antiviral (telaprevir, an HCV NS3-4A protease inhibitor) and peginterferon alfa-2a/ribavirin (PR) in patients with genotype 1 chronic hepatitis C (CHC). This model, which was parameterized with on-treatment data from early phase clinical studies in treatment-naïve patients, prospectively predicted sustained virologic response (SVR) rates that were comparable to observed rates in subsequent clinical trials of regimens with different treatment durations in treatment-naïve and treatment-experienced populations. The model explains the clinically-observed responses, taking into account the IC50, fitness, and prevalence prior to treatment of viral resistant variants and patient diversity in treatment responses, which result in different eradication times of each variant. The proposed model provides a framework to optimize treatment strategies and to integrate multifaceted mechanistic information and give insight into novel CHC treatments that include direct-acting antiviral agents

Oral Administration of GW788388, an Inhibitor of Transforming Growth Factor Beta Signaling, Prevents Heart Fibrosis in Chagas Disease

Cardiac damage and dysfunction are prominent features in patients with chronic Chagas disease, which is caused by infection with the protozoan parasite Trypanosoma cruzi (T. cruzi) and affects 10–12 million individuals in South and Central America. Our group previously reported that transforming growth factor beta (TGFß) is implicated in several regulatory aspects of T. cruzi invasion and growth and in host tissue fibrosis. In the present work, we evaluated the therapeutic action of an oral inhibitor of TGFß signaling (GW788388) administered during the acute phase of experimental Chagas disease. GW788388 treatment significantly reduced mortality and decreased parasitemia. Electrocardiography showed that GW788388 treatment was effective in protecting the cardiac conduction system, preserving gap junction plaque distribution and avoiding the development of cardiac fibrosis. Inhibition of TGFß signaling in vivo appears to potently decrease T. cruzi infection and to prevent heart damage in a preclinical mouse model. This suggests that this class of molecules may represent a new therapeutic tool for acute and chronic Chagas disease that warrants further pre-clinical exploration. Administration of TGFß inhibitors during chronic infection in mouse models should be further evaluated, and future clinical trials should be envisaged

Brazilian adolescents' knowledge and beliefs about abortion methods: A school-based internet inquiry

Background: Internet surveys that draw from traditionally generated samples provide the unique conditions to engage adolescents in exploration of sensitive health topics.Methods: We examined awareness of unwanted pregnancy, abortion behaviour, methods, and attitudes toward specific legal indications for abortion via a school-based internet survey among 378 adolescents aged 12-21 years in three Rio de Janeiro public schools.Results: Forty-five percent knew peers who had undergone an abortion. Most students (66.0%) did not disclose abortion method knowledge. However, girls (aOR 4.2, 95% CI 2.4-7.2), those who had experienced their sexual debut (aOR1.76, 95% CI 1.1-3.0), and those attending a prestigious magnet school (aOR 2.7 95% CI 1.4-6.3) were more likely to report methods. Most abortion methods (79.3%) reported were ineffective, obsolete, and/or unsafe. Herbs (e.g. marijuana tea), over-the-counter medications, surgical procedures, foreign objects and blunt trauma were reported. Most techniques (85.2%) were perceived to be dangerous, including methods recommended by the World Health Organization. A majority (61.4%) supported Brazil's existing law permitting abortion in the case of rape. There was no association between gender, age, sexual debut, parental education or socioeconomic status and attitudes toward legal abortion. However, students at the magnet school supported twice as many legal indications (2.7, SE.27) suggesting a likely role of peers and/or educators in shaping abortion views.Conclusions: Abortion knowledge and attitudes are not driven simply by age, religion or class, but rather a complex interplay that includes both social spaces and gender. Prevention of abortion morbidity and mortality among adolescents requires comprehensive sexuality and reproductive health education that includes factual distinctions between safe and unsafe abortion methods

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Front Matter

The carbohydrate Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) is produced in all mammals except for humans, apes and old world monkeys that lost the ability to synthetize this carbohydrate. Therefore, humans can produce high antibody titers against α-Gal. Anti-α-Gal IgE antibodies have been associated with tick-induced allergy (i.e. α-Gal syndrome) and anti-α-Gal IgG/IgM antibodies may be involved in protection against malaria, leishmaniasis and Chagas disease. The α-Gal on tick salivary proteins plays an important role in the etiology of the α-Gal syndrome. However, whether ticks are able to produce endogenous α-Gal remains currently unknown. In this study, the Ixodes scapularis genome was searched for galactosyltransferases and three genes were identified as potentially involved in the synthesis of α-Gal. Heterologous gene expression in α-Gal-negative cells and gene knockdown in ticks confirmed that these genes were involved in α-Gal synthesis and are essential for tick feeding. Furthermore, these genes were shown to play an important role in tick-pathogen interactions. Results suggested that tick cells increased α-Gal levels in response to Anaplasma phagocytophilum infection to control bacterial infection. These results provided the molecular basis of endogenous α-Gal production in ticks and suggested that tick galactosyltransferases are involved in vector development, tick-pathogen interactions and possibly the etiology of α-Gal syndrome in humans.This research was supported by the Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185). JJV was supported by Project FIT (Pharmacology, Immunotherapy, nanoToxicology), funded by the European Regional Development Fund.Peer Reviewe

Phylogenetic diversity of Amazonian tree communities

This is the peer reviewed version of the following article: Honorio Coronado, E. N., Dexter, K. G., Pennington, R. T., Chave, J., Lewis, S. L., Alexiades, M. N., Alvarez, E., Alves de Oliveira, A., Amaral, I. L., Araujo-Murakami, A., Arets, E. J. M. M., Aymard, G. A., Baraloto, C., Bonal, D., Brienen, R., Cerón, C., Cornejo Valverde, F., Di Fiore, A., Farfan-Rios, W., Feldpausch, T. R., Higuchi, N., Huamantupa-Chuquimaco, I., Laurance, S. G., Laurance, W. F., López-Gonzalez, G., Marimon, B. S., Marimon-Junior, B. H., Monteagudo Mendoza, A., Neill, D., Palacios Cuenca, W., Peñuela Mora, M. C., Pitman, N. C. A., Prieto, A., Quesada, C. A., Ramirez Angulo, H., Rudas, A., Ruschel, A. R., Salinas Revilla, N., Salomão, R. P., Segalin de Andrade, A., Silman, M. R., Spironello, W., ter Steege, H., Terborgh, J., Toledo, M., Valenzuela Gamarra, L., Vieira, I. C. G., Vilanova Torre, E., Vos, V., Phillips, O. L. (2015), Phylogenetic diversity of Amazonian tree communities. Diversity and Distributions, 21: 1295–1307. doi: 10.1111/ddi.12357, which has been published in final form at 10.1111/ddi.12357Aim: To examine variation in the phylogenetic diversity (PD) of tree communities across geographical and environmental gradients in Amazonia. Location: Two hundred and eighty-three c. 1 ha forest inventory plots from across Amazonia. Methods: We evaluated PD as the total phylogenetic branch length across species in each plot (PDss), the mean pairwise phylogenetic distance between species (MPD), the mean nearest taxon distance (MNTD) and their equivalents standardized for species richness (ses.PDss, ses.MPD, ses.MNTD). We compared PD of tree communities growing (1) on substrates of varying geological age; and (2) in environments with varying ecophysiological barriers to growth and survival. Results: PDss is strongly positively correlated with species richness (SR), whereas MNTD has a negative correlation. Communities on geologically young- and intermediate-aged substrates (western and central Amazonia respectively) have the highest SR, and therefore the highest PDss and the lowest MNTD. We find that the youngest and oldest substrates (the latter on the Brazilian and Guiana Shields) have the highest ses.PDss and ses.MNTD. MPD and ses.MPD are strongly correlated with how evenly taxa are distributed among the three principal angiosperm clades and are both highest in western Amazonia. Meanwhile, seasonally dry tropical forest (SDTF) and forests on white sands have low PD, as evaluated by any metric. Main conclusions: High ses.PDss and ses.MNTD reflect greater lineage diversity in communities. We suggest that high ses.PDss and ses.MNTD in western Amazonia results from its favourable, easy-to-colonize environment, whereas high values in the Brazilian and Guianan Shields may be due to accumulation of lineages over a longer period of time. White-sand forests and SDTF are dominated by close relatives from fewer lineages, perhaps reflecting ecophysiological barriers that are difficult to surmount evolutionarily. Because MPD and ses.MPD do not reflect lineage diversity per se, we suggest that PDss, ses.PDss and ses.MNTD may be the most useful diversity metrics for setting large-scale conservation priorities.FINCyT - PhD studentshipSchool of Geography of the University of LeedsRoyal Botanic Garden EdinburghNatural Environment Research Council (NERC)Gordon and Betty Moore FoundationEuropean Union's Seventh Framework ProgrammeERCCNPq/PELDNSF - Fellowshi