44 research outputs found
Uranotaenia novobscura ryukyuana (Diptera: Culicidae) Population Dynamics Are Denso-Dependent and Autonomous From Weather Fluctuations
Larvae of the mosquito Uranotaenia novobscura ryukyuana Tanaka et al., have been reported in tree-holes, bamboo stumps, and artiTcial water containers. So far, no study has addressed the role that density dependence and weather suctuations could have played in the abundance of this nonvector mosquito. A year-long study was conducted on the population dynamics of this mosquito using oviposition traps in Okinawa, Japan. Time series analysis and the Ricker population model were used to analyze the association between mosquito density and population growth and suctuations in relative humidity, temperature, and rainfall. Our results suggest that Ur. novobscura ryukyuana has stable denso-dependent dynamics, which are autonomous from weather suctuations. Our results were opposite to patterns observedin other subtropical mosquito species, whose population dynamics might be partially driven by weather suctuations, thus highlighting the diversity of responses that mosquitoes can have to changing environments
Recent Incidence of Human Malaria Caused by Plasmodium knowlesi in the Villages in Kudat Peninsula, Sabah, Malaysia: Mapping of The Infection Risk Using Remote Sensing Data
Plasmodium knowlesi (Pk) is a malaria parasite that naturally infects macaque monkeys in Southeast Asia. Pk malaria, the zoonosis transmitted from the infected monkeys to the humans by Anopheles mosquito vectors, is now a serious health problem in Malaysian Borneo. To createa strategic plan to control Pk malaria, it is important to estimate the occurrence of the disease correctly. The rise of Pk malaria has been explained as being due to ecological changes, especially deforestation. In this research, we analysed the time-series satellite images of MODIS (MODerate-resolution Imaging Spectroradiometer) of the Kudat Peninsula in Sabah and created the “Pk risk map” on which the Land-Use and Land-Cover (LULC) information was visualised. The case number of Pk malaria of a village appeared to have a correlation with the quantity of two specific LULC classes, the mosaic landscape of oil palm groves and the nearby land-use patches of dense forest, surrounding the village. Applying a Poisson multivariate regression with a generalized linear mixture model (GLMM), the occurrence of Pk malaria cases was estimated from the population and the quantified LULC distribution on the map. The obtained estimations explained the real case numbers well, when the contribution of another risk factor, possibly the occupation of the villagers, is considered. This implies that the occurrence of the Pk malaria cases of a village can be predictable from the population of the village and the LULC distribution shown around it on the map. The Pk risk map will help to assess the Pk malaria risk distributions quantitatively and to discover the hidden key factors behind the spread of this zoonosis
研究速報 : Making five atomic force microscope for 200,000yen each : A student project
特集2 日仏マイクロメカトロニクス国際共同研究組織(LIMMS
Changes in conditional net survival and dynamic prognostic factors in patients with newly diagnosed metastatic prostate cancer initially treated with androgen deprivation therapy
Background The purpose of this study was to identify predictive factors associated with conditional net survival in patients with metastatic hormone-naive prostate cancer (mHNPC) initially treated with androgen deprivation therapy (ADT). Methods At nine hospitals in Tohoku, Japan, the medical records of 605 consecutive patients with mHNPC who initially received ADT were retrospectively reviewed. The Pohar Perme estimator was used to calculate conditional net cancer-specific survival (CSS) and overall survival (OS) for up to 5 years subsequent to the diagnosis. Using multiple imputation, proportional hazard ratios for conditional CSS and OS were calculated with adjusted Cox regression models. Results During a median follow up of 2.95 years, 208 patients died, of which 169 died due to progressive prostate cancer. At baseline, the 5-year CSS and OS rates were 65.5% and 58.2%, respectively. Conditional 5-year net CSS and OS survival gradually increased for all the patients. In patients given a 5-year survivorship, the conditional 5-year net CSS and OS rates improved to 0.906 and 0.811, respectively. Only the extent of disease score (EOD) >= 2 remained a prognostic factor for CSS and OS up to 5 years; as survival time increased, other variables were no longer independent prognostic factors. Conclusions The conditional 5-year net CSS and OS in patients with mHNPC gradually increased; thus, the risk of mortality decreased with increasing survival. The patient\u27s risk profile changed over time. EOD remained an independent prognostic factor for CSS and OS after 5-year follow-up. Conditional net survival can play a role in clinical decision-making, providing intriguing information for cancer survivors
Prognostic significance of early changes in serum biomarker levels in patients with newly diagnosed metastatic prostate cancer
We evaluated the impact of early changes in serum biomarker levels on the survival of patients with metastatic hormone-sensitive prostate cancer (mHSPC) who were initially treated with androgen deprivation therapy (ADT). We retrospectively investigated 330 patients with mHSPC whose serum maker levels were at baseline and at 2-4 months. An optimal Cox regression model was established with the highest optimism-corrected concordance index based on 10-fold cross-validation. The median cancer-specific survival (CSS) and overall survival (OS) were 7.08 and 6.47 years (median follow-up, 2.53 years), respectively. In the final optimal Cox model with serum biomarker levels treated as time-varying covariates, prostate-specific antigen (PSA), hemoglobin (Hb), and alkaline phosphatase (ALP) significantly increased the risk of poor survival in the context of both CSS and OS. Kaplan-Meier curves stratified by the three risk factors of high PSA, low Hb and high ALP desmondtated that median OS were not reached with none of these factors, 6.47 years with one or two factors, and 1.76 years with all three factors. Early changes in serum biomarker levels after ADT may be good prognostic markers for the survival of patients with mHSPC
Mosquito Biodiversity Patterns Around Urban Environments in South-Central Okinawa Island, Japan
Okinawa is the largest, most urbanized, and densely populated island in the Ryukyus Archipelago, where mosquito species diversity has been thoroughly studied. However, the south-central Okinawa mosquito fauna has been relatively poorly studied. Here, we present results from a mosquito faunal survey in urban environments of Nishihara city, south-central Okinawa. Mosquitoes were sampled biweekly, from April 2007 to March 2008, at 3 different environments: a forest preserve, an animal farm, and a water reservoir. We employed 4 mosquito collection methods: 1) oviposition traps; 2) light traps; 3) sweep nets; and 4) larval surveys of tree holes, leaf axils, and artificial water containers. We collected a total of 568 adults and 10,270 larvae belonging to 6 genera and 13 species, including 6 species of medical importance: Aedes albopictus, Armigeres subalbatus, Anopheles Hyrcanus group, Culex bitaeniorhynchus, Cx. quinquefasciatus, and Cx. tritaeniorhynchus. Mosquito species composition was similar to data from previous studies in Okinawa Island. The flattening of the species accumulation curve suggests that our diversity sampling was exhaustive with light and oviposition traps, as well as the coincidence between the species richness we found in the field and estimates from the Chao2 index, a theoretical estimator of species richness based on species abundance. This study highlights the importance of combining several sampling techniques to properly characterize regional mosquito fauna and to monitor changes in the presence of mosquito species
Serological Surveillance Development for Tropical Infectious Diseases Using Simultaneous Microsphere-Based Multiplex Assays and Finite Mixture Models
Background:A strategy to combat infectious diseases, including neglected tropical diseases (NTDs), will depend on the development of reliable epidemiological surveillance methods. To establish a simple and practical seroprevalence detection system, we developed a microsphere-based multiplex immunoassay system and evaluated utility using samples obtained in Kenya.Methods:We developed a microsphere-based immuno-assay system to simultaneously measure the individual levels of plasma antibody (IgG) against 8 antigens derived from 6 pathogens: Entamoeba histolytica (C-IgL), Leishmania donovani (KRP42), Toxoplasma gondii (SAG1), Wuchereria bancrofti (SXP1), HIV (gag, gp120 and gp41), and Vibrio cholerae (cholera toxin). The assay system was validated using appropriate control samples. The assay system was applied for 3411 blood samples collected from the general population randomly selected from two health and demographic surveillance system (HDSS) cohorts in the coastal and western regions of Kenya. The immunoassay values distribution for each antigen was mathematically defined by a finite mixture model, and cut-off values were optimized.Findings:Sensitivities and specificities for each antigen ranged between 71 and 100%. Seroprevalences for each pathogen from the Kwale and Mbita HDSS sites (respectively) were as follows: HIV, 3.0% and 20.1%; L. donovani, 12.6% and 17.3%; E. histolytica, 12.8% and 16.6%; and T. gondii, 30.9% and 28.2%. Seroprevalences of W. bancrofti and V. cholerae showed relatively high figures, especially among children. The results might be affected by immunological cross reactions between W. bancrofti-SXP1 and other parasitic infections; and cholera toxin and the enterotoxigenic E. coli (ETEC), respectively.Interpretation:A microsphere-based multi-serological assay system can provide an opportunity to comprehensively grasp epidemiological features for NTDs. By adding pathogens and antigens of interest, optimized made-to-order high-quality programs can be established to utilize limited resources to effectively control NTDs in Africa
Density dependence in a seasonal time series of the bamboo mosquito, Tripteroides bambusa (Diptera: Culicidae)
The bamboo mosquito, Tripteroides bambusa (Yamada) (Diptera: Culicidae), is a
mosquito species ubiquitous across forested landscapes in Japan. During 2014 we sampled adult
mosquitoes from May to November using a sweep net in Nagasaki, Japan. We recorded and managed our
field data using Open Data Kit, which eased the overall process of data management before performing
their statistical analysis. Here, we analyse the resulting biweekly time series of the bamboo mosquito
abundance using time-series statistical techniques. Specifically, we test for density dependence in the
population dynamics fitting the Ricker model. Parameter estimates for the Ricker model suggest that the
bamboo mosquito is under density dependence regulation and that its population dynamics is stable. Our
data also suggest the bamboo mosquito increased its abundance when temperature was more variable at
our study site. Further work is warranted to better understand the linkage between the observed density
dependence in the adults and the larvae of this mosquito species.-El mosquito del bambú, Tripteroides bambusa (Yamada) (Diptera: Culicidae), es una
especie de mosquito omnipresente en los paisajes forestales de Japón. Durante 2014 se tomaron muestras de mosquitos
mosquitos adultos de mayo a noviembre utilizando una red de barrido en Nagasaki, Japón. Registramos y gestionamos nuestros
datos de campo utilizando Open Data Kit, lo que facilitó el proceso general de gestión de datos antes de realizar
su análisis estadístico. Aquí analizamos las series temporales quincenales resultantes de la abundancia del mosquito del bambú
bambú mediante técnicas estadísticas de series temporales. En concreto, comprobamos la dependencia de la densidad en la
dinámica de la población ajustando el modelo de Ricker. Las estimaciones de los parámetros del modelo de Ricker sugieren que el
mosquito del bambú está bajo regulación de dependencia de la densidad y que su dinámica poblacional es estable. Nuestros datos de
datos también sugieren que el mosquito del bambú aumentó su abundancia cuando la temperatura fue más variable en
en el lugar de estudio. Es necesario seguir trabajando para comprender mejor la relación entre la dependencia de la densidad observada en los adultos y en las larvas.
observada en los adultos y las larvas de esta especie de mosquito.Universidad Nacional, Costa Rica.Escuela de Medicina Veterinari