Efecto del tamaño de pólipo y de los exudados de corales sobre la dinámica de picoeucariotas en un ambiente controlado

We examined the ability of scleractinian corals with different polyp sizes to remove picoeukaryotes by predation and the effect of coral exudates on picoeukaryote growth. Experiments were conducted by adding picoeukaryotes to Stylophora pistillata (SP) and Montipora stellata (MS). Within six hours the picoeukaryote concentration in the SP and MS tanks was significantly lower than the control without corals. SP showed higher overall activity than MS, and the particle removal activity of MS decreased in light conditions. Picoeukaryotes exposed to SP exudates grew significantly denser than those exposed to MS exudates or those in water without coral exudates. Dissolved organic carbon concentrations in the SP tanks were also significantly higher. We concluded that the picoeukaryote removal rates were higher in S. pistillata than in M. stellata, and coral exudates can reciprocally enhance picoeukaryote growth.Hemos estudiado la capacidad de corales escleractinios con diferentes tamaños de pólipo de depredar picoplancton eucariótico, y también el efecto de los exudados de los corales sobre el crecimiento de picoplancton eucariótico. Los experimentos se realizaron añadiendo picoplancton eucariótico a Stylophora pistillata (SP) y Montipora stellata (MS). Después de 6 horas, las concentraciones de picoplancton eucariótico en los tanques de SP y MS fueron significativamente reducidas, en comparación con las del tanque control sin coral. SP mostró en general una actividad depredadora algo más grande que MS, y éste redujo su actividad en condiciones de luz. Los picoeucariotas expuestos a exudados de SP llegaron a concentraciones más altas que cuando fueron expuestos a exudados de MS o a agua sin corales. La concentración de carbono orgánico disuelto en los tanques de SP también fué significativamente más alta. Se concluye que las tasas de depredación sobre los picoeukaryotes fueron más altas con S. pistillata que con M. stellata, y que los exudados del coral pueden recíprocamente mejorar el crecimiento de picoplancton eucariótico

Temporal and Spatial Variations in spatial variations in symbiont communities of catch bowl coral Isopora palifera (Scleractinia: Acroporidae) on reefs in Kenting National Park, Taiwan

Acclimatization through Symbiodinium shuffling is one of potential mechanisms in reef-building corals to survive environmental stress. In our previous study, the catch bowl coral Isopora palifera in Tantzei Bay (TZB), Nanwan, Kenting National Park (KNP), southern Taiwan was demonstrated to shuffle thermal-tolerant Symbiodinium D1a and thermal-sensitive Symbiodinium C3 in response to seasonal variations in sea surface temperatures (SSTs) in 2000 and 2001. In this study, we reexamined the temporal dynamics of the Symbiodinium community of I. palifera in TZB in 2006-2009. In addition, spatial variations in Symbiodinium communities in I. palifera were also examined at 6 other sites of Nanwan, KNP in 2009, including a site located at a nuclear power plant outlet (NPP-OL) in southern Taiwan with a yearly mean SST 0.6-1.5 degrees C higher compared to the other sites. Phylotyping and DNA sequence analyses of Symbiodinium ribosomal 28S and ITS2 markers showed that I. palifera colonies at TZB continued to show seasonal shuffling, but shifted to thermal-sensitive type C3 dominant in 2006-2009. This differed from the symbiont community originally dominated by the thermal-tolerant Symbiodinium D1a in 2000 and 2001 after the 1998 mass-bleaching event. Significant differences in spatial variations of the symbiont community in Nanwan were detected with I. palifera colonies at the NPP-OL dominated by Symbiodinium D1a. Our study results suggest that I. palifera can acclimatize to SST anomalies by shuffling to thermal-tolerant Symbiodinium D1a and can revert to thermal-sensitive C3 when the stress disappears, but will maintain the thermally tolerant Symbiodinium D1a as the dominant symbiont if the heat stress continues

A Model to Predict Total Chlorine Residue in the Cooling Seawater of a Power Plant Using Iodine Colorimetric Method

A model experiment monitoring the fate of total residue oxidant (TRO) in water at a constant temperature and salinity indicated that it decayed exponentially with time, and with TRO decaying faster in seawater than in distilled water. The reduction of TRO by temperature (°K) was found to fit a curvilinear relationship in distilled water (r2 = 0.997) and a linear relationship in seawater (r2 = 0.996). Based on the decay rate, flow rate, and the length of cooling water flowing through at a given temperature, the TRO level in the cooling water of a power plant could be estimated using the equation developed in this study. This predictive model would provide a benchmark for power plant operators to adjust the addition of chlorine to levels necessary to control bio-fouling of cooling water intake pipelines, but without irritating ambient marine organisms

Impacts of Seagrass on Benthic Microalgae and Phytoplankton Communities in an Experimentally Warmed Coral Reef Mesocosm

The effects of seagrass on microalgal assemblages under experimentally elevated temperatures (28°C) and CO2 partial pressures (pCO2; 800 μatm) were examined using coral reef mesocosms. Concentrations of nitrate, ammonium, and benthic microalgal chlorophyll a (chl-a) were significantly higher in seagrass mesocosms, whereas phytoplankton chl-a concentrations were similar between seagrass and seagrass-free control mesocosms. In the seagrass group, fewer parasitic dinoflagellate OTUs (e.g., Syndiniales) were found in the benthic microalgal community though more symbiotic dinoflagellates (e.g., Cladocopium spp.) were quantified in the phytoplankton community. Our results suggest that, under ocean acidification conditions, the presence of seagrass nearby coral reefs may (1) enhance benthic primary productivity, (2) decrease parasitic dinoflagellate abundance, and (3) possibly increase the presence of symbiotic dinoflagellates

Recurrent disturbances and the degradation of hard coral communities in Taiwan

Recurrent disturbances can have a critical effect on the structure and function of coral reef communities. In this study, long-term changes were examined in the hard coral community at Wanlitung, in southern Taiwan, between 1985 and 2010. In this 26 year interval, the reef has experienced repeated disturbances that include six typhoons and two coral-bleaching events. The frequency of disturbance has meant that species susceptible to disturbance, such as those in the genus Acropora and Montipora have almost disappeared from the reef. Indeed, almost all hard coral species have declined in abundance, with the result that total hard coral cover in 2010 (17.7%) was less than half what it was in 1985 (47.5%). In addition, macro-algal cover has increased from 11.3% in 2003 to 28.5% in 2010. The frequency of disturbance combined with possible chronic influence of a growing human population mean that a diverse reef assemblage is unlikely to persist on this reef into the future

Immunity duration of a recombinant adenovirus type-5 vector-based Ebola vaccine and a homologous prime-boost immunisation in healthy adults in China: fi nal report of a randomised, double-blind, placebo-controlled, phase 1 trial

Background The 2013–15 Ebola virus disease epidemic in west Africa greatly accelerated the development of Ebola vaccine. We aimed to analyse the immune persistence induced by one shot of an adenovirus type-5 vector-based Ebola virus vaccine up to 6 months and the eff ect of boosting with a homologous vector in healthy adults in China. Methods In a randomised, double-blind, placebo-controlled, phase 1 clinical trial in one site in Jiangsu Province, China, 120 healthy adults aged 18–60 years received an initial dose of intramuscular adenovirus type-5 Ebola virus vaccine of 4·0 × 10¹⁰ viral particles, 1·6 × 10¹¹ viral particles, or placebo, and were followed up to day 168. Participants were subsequently re-recruited to receive a booster dose of the same vaccine or placebo, in the same dose, at month 6. Women who were pregnant, breastfeeding, or planned to become pregnant during the next month were excluded. Randomisation was conducted by computer-generated block randomisation. Randomisation data were unmasked for interim analysis of the data obtained between days 0–28 but not disclosed to participants or site staff . Safety and immunogenicity analysis were done on the intention-to-treat population. We aimed to assess the safety profi le of the experimental vaccine and the immunity responses to a single-dose immunisation or a homologous prime-boost regimen. Primary outcomes were Ebola glycoprotein-specifi c ELISA antibody responses 28 days post-boost and the occurrences of adverse reactions post-boost. The original trial and the extended booster study were registered with ClinicalTrials.gov, numbers NCT02326194 and NCT02533791, respectively. Findings Between Dec 28, 2014, and Jan 9, 2015, we enrolled 210 volunteers. 90 participants were not randomised due to not meeting inclusion criteria (61), meeting exclusion criteria (4), or withdrawal of consent (25). 120 people were randomly assigned to receive intramuscular Ebola vaccine at 4·0 × 10¹⁰ viral particles (low dose, n=40), Ebola vaccine at 1·6 × 10¹¹ viral particles (high dose, n=40), or placebo (n=40, in two groups of 20). After prime vaccination, the geometric mean titer (GMT) of ELISA EC90 peaked at 682·7 (95% CI 424·3–1098·5) in the low-dose vaccine group and 1305·7 (970·1–1757·2) in the high-dose vaccine group at day 28, and then fell gradually through the next a few months to 575·5 (394·8–838·8) in the high-dose vaccine group and 197·9 (107·9–362·7) in the low-dose vaccine group at day 168. No specific response was recorded in the placebo group with a GMT of 5·0. Of the 120 participants involved in the initial trial, ten participants declined to participate, and 110 were included in the boost immunisation: 38 received the low dose, 35 received the high dose, and 37 received the placebo. At day 28 after boost vaccination, the ELISA EC90 titres rapidly rose to 6110 (95% CI 4705–7935) in the low-dose group and to 11825 (8904–15705) in the high dose group. 78 of 110 participants reported at least one solicited adverse reaction within the fi rst 7 days after booster administration. Both of the groups who received vaccine showed signifi cantly higher incidence of mild or moderate solicited adverse reactions than did the placebo group. Interpretation The adenovirus 5-vectored Ebola vaccine of 1·6 × 10¹¹ viral particles was highly immunogenic and safe. The lower dose of 4·0 × 10¹⁰ viral particles was also safe, but immunogenicity seemed to be more vulnerable to the pre-existing immunity of adenovirus 5. A homologous priming-boosting regimen with adenovirus type-5 Ebola vaccine at 6 months interval was able to elicit greater antibody responses with longer duration. These results support an immunisation strategy to implement a booster injection for a more durable protection against Ebola virus disease

Structure-Based Discovery of Highly Selective Phosphodiesterase-9A Inhibitors and Implications for Inhibitor Design

A new series of phosphodiesterase-9 (PDE9) inhibitors that contain a scaffold of 6-amino-pyrazolopyrimidinone have been discovered by a combination of structure-based design and computational docking. This procedure significantly saved load of chemical synthesis and is an effective method for the discovery of inhibitors. The best compound 28 has an IC50 of 21 nM and 3.3 µM respectively for PDE9 and PDE5, and about three orders of magnitude of selectivity against other PDE families. The crystal structure of the PDE9 catalytic domain in complex with 28 has been determined and shows a hydrogen bond between 28 and Tyr424. This hydrogen bond may account for the 860-fold selectivity of 28 against PDE1B, in comparison with about 30-fold selectivity of BAY73-6691. Thus, our studies suggest that Tyr424, a unique residue of PDE8 and PDE9, is a potential target for improvement of selectivity of PDE9 inhibitors

Reliability and construct validity of two versions of Chalder Fatigue Scale among the general population in Mainland China

The 14-item Chalder Fatigue Scale (CFS) is widely used, while the 11-item version is seldom to be found in current research in mainland China. The objectives of the present study is to compare the reliability and construct validity between these two versions and to confirm which may be better for the mainland Chinese setting. Based on a cross-sectional health survey with a constructive questionnaire, 1887 individuals aged 18 years or above were selected. Socio-demographic, health-related, gynecological data were collected, and 11-item and 14-item Chalder Fatigue Scale (CFS) were used to assess fatigue. Confirmatory factor analysis and exploratory structural equation modeling (ESEM) were performed to test the fit of models of the two versions. Confirmatory factor analysis of the two versions of CFS did not support the two-factor theorized models. In addition, a three-factor ESEM model of the 11-item version, but not the 14-item version, showed better factor structure and fitness than the other models examined. Both the versions had good internal consistency reliability and a satisfactory internal consistency (Ω = 0.78–0.96, omega coefficient indicates the internal consistency reliability) was obtained from the optimal model. This study provided evidence for satisfactory reliability and structural validity for the three-factor model of the 11-item version, which was proven to be superior to the 14-item version for this data.This study was funded by by the Guangzhou 121 Talents Program (GZRSH-2014-2048, Guangzhou Municipal Human Resources and Social Security Bureau, P.R. China.)Published onlin

Factors associated with fatigue among men aged 45 and older: A cross-sectional study

Background and Purpose: Fatigue is one of the most common symptoms reported in several studies; but few studies have concentrated on the male population, especially for the middle-aged and older men who are exposed to greater fatigue risk. The purpose of this study was to explore the prevalence of fatigue and identify the risk factors of fatigue among men aged 45 and older in China. Methods: This study was part of a cross-sectional study on community health in Shunde (Guangdong Province, China). A total sample of 1158 men aged 45 and older were included. Sociodemographic characteristics, health and lifestyle factors and the Chalder Fatigue Scale (CFS) were measured by structured questionnaires through face-to-face interviews. Multivariate logistic regression was applied to determine the risk factors of fatigue. Results: Approximately 30% of participants experienced fatigue. Older age (≥75 years: adjusted OR 3.88, 95% CI 2.09–7.18), single marital status (1.94, 1.04–3.62), unemployed status (1.68, 1.16–2.43), number of self-reported chronic diseases (≥2 chronic diseases: 2.83, 1.86–4.31), number of individuals’ children (≥4 children: 2.35, 1.33–4.15), hospitalization in the last year (1.61, 1.03–2.52) were all significantly associated with increased risk of fatigue, while regular exercise (0.46, 0.32–0.65) was a protective factor against fatigue. Conclusions: Fatigue was usual in males and several factors were associated with the fatigue. These findings may have implication in risk assessment of fatigue and help in developing and implementing targeted interventions in middle-aged and elderly males.This study was supported by the Guangzhou 121 Talents Program. JJW is supported by the Guangdong Exemplary Centres for Exploratory Teaching in Higher Education Institutions—General Practice Exploratory Teaching Centre GDJG-2010-N38-35, Guangdong Department of Education, China, and The Ninth Round of Guangdong Key Disciplines—General Practice GDJY-2012-N13-85, Guangdong Department of Education, China.Published onlin