Intraspecific life-history and morphological variations in Lymnaea peregra (Müller) (Gastropoda : Pulmonata) : environmental or genetic variance?

Three neighbouring populations of Lymnaea peregra were studied between January 1985 and December 1986. The populations differed in egg sizes, juvenile growth rates, survival regimes, breeding patterns, and total reproductive efforts. Differences in water temperatures were largely responsible for the annual variation in the timing of the breeding seasons while interpopulation divergence in growth rates, and consequently number of breeding bouts per year, was attributed mainly to varying food availability. Snails at the Don site had lower winter mortalities than the Sheaf and the Rivelin individuals, partly due to the higher winter temperatures at the former site. Moreover, faster current speeds might also be responsible for the higher mortalities at the Sheaf and the Rivelin than the Don site. The lower reproductive efforts exhibited by the Don snails as compared with the other two populations were ascribed to the low food availability, high population density and shortage of oviposition sites at the Don. The Don snails consistently started breeding earlier than the Sheaf and the Rivelin individuals. Mass-culture and controlled breeding experiments revealed that the early-breeding trait of the Don snails was heritable, and probably genetically fixed. It is postulated that the early breeding of the Don snails is an adaptation to exploit a longer breeding season. Quantitative genetical analyses indicated a genetic trade-off between the age at first reproduction and the hatchling size of the Don snails. Similar analyses also showed significant genetic variances for the juvenile growth rates and the hatchling size in the Sheaf and the Rivelin populations respectively. There is some suggestion that the snail populations showed varying reproductive investment per individual offspring as predicted by the Sibly & Calow model. This study shows that L. peregra, though primarily phenotypically plastic, can evolve local adaptations according to specific ecological circumstances

Pharmaceuticals in tap water: human health risk assessment and proposed monitoring framework in China

Background: Pharmaceuticals are known to contaminate tap water worldwide, but the relevant human health risks have not been assessed in China. Objectives: We monitored 32 pharmaceuticals in Chinese tap water and evaluated the life-long human health risks of exposure in order to provide information for future prioritization and risk management. Methods: We analyzed samples (n = 113) from 13 cities and compared detected concentrations with existing or newly-derived safety levels for assessing risk quotients (RQs) at different life stages, excluding the prenatal stage. Results: We detected 17 pharmaceuticals in 89% of samples, with most detectable concentrations (92%) at < 50 ng/L. Caffeine (median-maximum, nanograms per liter: 24.4-564), metronidazole (1.8-19.3), salicylic acid (16.6-41.2), clofibric acid (1.2-3.3), carbamazepine (1.3-6.7), and dimetridazole (6.9-14.7) were found in ≥ 20% of samples. Cities within the Yangtze River region and Guangzhou were regarded as contamination hot spots because of elevated levels and frequent positive detections. Of the 17 pharmaceuticals detected, 13 showed very low risk levels, but 4 (i.e., dimetridazole, thiamphenicol, sulfamethazine, and clarithromycin) were found to have at least one life-stage RQ ≥ 0.01, especially for the infant and child life stages, and should be considered of high priority for management. We propose an indicator-based monitoring framework for providing information for source identification, water treatment effectiveness, and water safety management in China. Conclusion: Chinese tap water is an additional route of human exposure to pharmaceuticals, particularly for dimetridazole, although the risk to human health is low based on current toxicity data. Pharmaceutical detection and application of the proposed monitoring framework can be used for water source protection and risk management in China and elsewhere

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase&nbsp;1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation&nbsp;disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age&nbsp; 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score&nbsp; 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc&nbsp;= 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N&nbsp;= 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in&nbsp;Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in&nbsp;Asia&nbsp;and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Ecological studies of litter production and decomposition in a mixed forest in Hong Kong with special reference to ficus fistulosa reinv.ex B1. (moraceae)

published_or_final_versionZoologyMasterMaster of Philosoph

The environmental characteristics of usage of coal gangue in bricking-making: A case study at Huainan, China

The behaviors of natural radionuclides and toxic elements during coal gangue brick making processes are described. A simulation experiment of coal gangue brick firing was carried out to evaluate the enrichments of natural radionuclides and volatilizations of elements. Simultaneous sampling of coal gangue and corresponding combustion product (slag) was performed. The radioactivities of the radionuclide were determined by high-purity germanium gamma ray spectrometer, and the concentrations of toxic elements were analyzed by ICP-MS. Results have shown that the level of natural radionuclides may not cause immediate or acute environmental impacts because the Ra-eq values and H-ex (in the brick) are 345 Bq kg(-1) and 0.89, lower than the limit values of 370 Bq kg(-1), and 1, respectively. However, the Ra-eq and H-ex values are near the limit values, their chronic-environmental and health impacts should be considered noteworthy. The elements found in the emission could be categorized into two types: non-volatilized elements (Co, Cr, Mn and V) and volatilized elements (As, Cd, Cu, Ni, Se, Sn and Zn). Understanding the behaviors of natural radionuclides and toxic elements during brick making processes is helpful for the assessment of their potential impacts to human health and the environment. (C) 2013 Elsevier Ltd. All rights reserved

Distribution and assessment of Pb in the supergene environment of the Huainan Coal Mining Area, Anhui, China

Coal mining area is highly subject to lead (Pb) pollution from coal mining activities. Several decades of coal mining and processing practices in dozens of coal mines in the Huainan Coal Mining Area (HCMA) have led to the accumulation of massive amounts of coal gangue, which piled in dumps. In order to investigate the impacts of coal gangue dumps on Pb level in the supergene media of the HCMA, a systematic sampling campaign comprising coal gangue, soil, wheat, and earthworm samples was conducted. The average Pb content in the coal mining area soil is 24 mg/kg, which is slightly higher than the associated coal gangues (23 mg/kg) and markedly higher than reference region soil (12.6 mg/kg). Soil in the HCMA present a slight to moderate Pb contamination, which might be related to the weathering and leaching of coal gangue dumps. Lateral distribution of Pb in HCMA soil differed among individual coal mines. The soil profile distribution of Pb depends on both natural and anthropogenic contributions. Average Pb content is higher in roots than in stems, leaves, and wheat husks, while the Pb level in seeds exceeded the maximum Pb allowance for foods (Maximum Levels of Contaminants in Foods of China, GB 2762-2012). Earthworms in the selected area are significantly enriched in Pb, suggesting higher bio-available Pb level in soil in the HCMA

Effect of ash composition on the partitioning of arsenic during fluidized bed combustion

The effect of the ash composition on the redistribution of arsenic in a coal combustion system was determined via both experimental laboratory simulations and thermodynamic equilibrium calculations. The experimental study was performed in a fluidized bed reactor in combustion temperature range of 500-1000 degrees C. The results show that arsenic redistribution is strongly related to the chemical composition of coal in a combustion system. The presence of Fe, Ca, Mg, Al, Na and K favour arsenic retention, while Si causes an opposing effect. The arsenic retention on ash compositions is both temperature and amount dependent. With rising combustion temperature, the arsenic retention efficiency of Fe, Ca and Mg oxides augmented up to a maximum and then decreased, while those of Al, Na and K compounds continued expanding in the range of 500-1000 degrees C. Chemical adsorption may be the primary mechanism for Fe, Ca, Mg, K and Na, while the adsorption of arsenic by Al may be ascribed to both physical and chemical adsorption. Arsenic is captured in ashes as a result of the formation of stable arsenate compounds arising from interactions with the inorganic matrix. The negative arsenic retention effect by silica is attributed to reactions with ash compositions which promote arsenic capture and the reduction of the solid arsenic compounds. (C) 2017 Elsevier Ltd. All rights reserved

Retention mechanisms of ash compositions on toxic elements (Sb, Se and Pb) during fluidized bed combustion

Both laboratory simulation experiments and thermodynamic equilibrium calculations were conducted to illustrate the retention mechanisms of ash components on three toxic elements (Sb, Se and Pb). The experiment was carried out in a fluidized bed reactor with the combustion temperature in the range of 500-1000 degrees C. The results shown that the redistribution behavior of these toxic elements was greatly proportional to the combustion temperature, ash components and amounts. The adding of Fe, Ca, Mg, Na and K favour the retention of Sb and Se, while the presence of Si was represented against Sb and Se capture. Si, Al, Fe, Na and K have an appreciable effect on the retention of Pb, while the Pb capture by Ca and Mg was limited. The partial retention of these elements in ashes may be attributed to both physisorption and chemisorption. Among them, the formation of non- volatilized compounds may be the primary contribution for the retention of Sb, Se and Pb (except for Al). The negative Sb and Se captured by Si may be ascribed to the interactions between Si and other components which promote the retention of Sb and Se. The highly Pb retention by Si and Al in ashes may be explained by the formation of PbO center dot SiO2, PbO center dot Al2O3 and PbO center dot Al2O3 center dot 2SiO(2). Fe- and Al-based materials may be supposed to the appreciate additives for the capture potential of all the selected elements