Improving tree survival prediction with forecast combination and disaggregation.

Abstract: The tree mortality model plays an important role in simulating stand dynamic processes. Past work has shown that the disaggregation method was successful in improving tree survival prediction. This method was used in this study to forecast tree survival probability of Chinese pine (Pinus tabulaeformis Carrière) in Beijing. Outputs from the tree survival model were adjusted from either the stand-level model prediction or the combined estimator from the forecast combination method. Our results show that the disaggregation approach improved the performance of tree survival models. We also showed that stand-level prediction played a crucial role in refining outputs from a tree survival model, especially when it is a very simple model. Because the forecast combination method produced better stand-level prediction, we prefer the use of this method in conjunction with the disaggregation approach, even though the performance gain in using the forecast combination method shown for this data set was modest. Résumé : La modélisation de la mortalité des arbres joue un rôle important dans la simulation des processus dynamiques de la croissance forestière. Les travaux antérieurs ont montré que la méthode de désagrégation pouvait améliorer la prédic-tion de la survie des arbres. Cette méthode a donc été utilisée ici pour prédire la probabilité de survie du pin de Chine (Pinus tabulaeformis Carrière) à Pékin. Les extrants du modèle de survie des arbres ont été ajustés à partir soit de la prédiction du modèle à l'échelle du peuplement, soit de l'estimateur combiné de la méthode de combinaison des prédictions. Nos ré-sultats montrent que l'approche de désagrégation a amélioré la performance du modèle de survie des arbres. Nous avons également montré que la prédiction à l'échelle du peuplement a joué un rôle crucial dans le raffinement des extrants du modèle de survie des arbres, surtout lorsque le modèle est très simple. Comme la méthode de combinaison des prédictions pré-dit le mieux les attributs du peuplement, nous préférons l'utiliser conjointement avec la méthode de désagrégation, même si le gain de performance était modeste pour l'ensemble de données considéré. [Traduit par la Rédaction

Determination of dezocine in rabbit plasma by liquid chromatography-mass spectrometry and its application

A sensitive and selective liquid chromatography-mass spectrometry (LC–MS) method for determination of dezocine in rabbit plasma was developed and validated. After addition of diazepam as internal standard (IS), liquid–liquid extraction (LLE) was used for sample preparation, and chromatography involved Agilent SB-C18 column (2.1 mmx50 mm, 3.5 um) using 0.1 % formic acid in water and acetonitrile as a mobile phase with gradient elution. Detection involved positive ion mode electrospray ionization (ESI), and selective ion monitoring (SIM) mode was used for quantification of target fragment ions m/z 245.8 for dezocine and m/z 284.8 for diazepam (internal standard, IS). The assay was linear over the range of 5–500 ng/mL for dezocine, with a lower limit of quantitation (LLOQ) of 5 ng/mL for dezocine. Intra- and inter-day precisions were less than 13 % and the accuracies were in the range of 93.1-105.2 % for dezocine. This developed method was successfully applied for the determination of dezocine in rabbit plasma for pharmacokinetic study.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Global prevalence of Cryptosporidium spp. in pigs: a systematic review and meta-analysis

Cryptosporidium spp. are significant opportunistic pathogens causing diarrhoea in humans and animals. Pigs are one of the most important potential hosts for Cryptosporidium. We evaluated the prevalence of Cryptosporidium in pigs globally using published information and a random-effects model. In total, 131 datasets from 36 countries were included in the final quantitative analysis. The global prevalence of Cryptosporidium in pigs was 16.3% (8560/64 809; 95% confidence interval [CI] 15.0–17.6%). The highest prevalence of Cryptosporidium in pigs was 40.8% (478/1271) in Africa. Post-weaned pigs had a significantly higher prevalence (25.8%; 2739/11 824) than pre-weaned, fattening and adult pigs. The prevalence of Cryptosporidium was higher in pigs with no diarrhoea (12.2%; 371/3501) than in pigs that had diarrhoea (8.0%; 348/4874). Seven Cryptosporidium species (Cryptosporidium scrofarum, Cryptosporidium suis, Cryptosporidium parvum, Cryptosporidium muris, Cryptosporidium tyzzeri, Cryptosporidium andersoni and Cryptosporidium struthioni) were detected in pigs globally. The proportion of C. scrofarum was 34.3% (1491/4351); the proportion of C. suis was 31.8% (1385/4351) and the proportion of C. parvum was 2.3% (98/4351). The influence of different geographic factors (latitude, longitude, mean yearly temperature, mean yearly relative humidity and mean yearly precipitation) on the infection rate of Cryptosporidium in pigs was also analysed. The results indicate that C. suis is the dominant species in pre-weaned pigs, while C. scrofarum is the dominant species in fattening and adult pigs. The findings highlight the role of pigs as possible potential hosts of zoonotic cryptosporidiosis and the need for additional studies on the prevalence, transmission and control of Cryptosporidium in pigs

A Marked Decline in Taenia solium Taeniasis and Cysticercosis Infections in China: Possible Reasons from the Ecological Determinants Perspective

Taenia solium taeniasis/cysticercosis is an important global food-borne infectious disease transmitted between humans and pigs. According to both national surveys and field investigations, the prevalence of the disease in China has significantly decreased in recent decades. The primary disease control measures are health education and promotion, meat inspection, and chemotherapy. Other factors that influence or fundamentally affect human and pig T. solium taeniasis/cysticercosis have been identified, such as pig farming patterns shift and a revolution in sanitary toilets, which block T. solium transmission routes. Pig farming practices have shifted from backyard to large-scale intensive farming, thus decreasing pig contact with, and consumption of, human excreta. The increased in the use of sanitary toilets has facilitated hygiene by preventing of human excreta from contacting humans, or polluting the environment, feed, or water. The occurrence of human T. solium infections has markedly decreased as a result of these social changes. The objective of this review is to describe the ecological determinants of the cysticercosis decline in China

ANALYSIS OF STRUCTURAL CHANGES OF MASSON PINE LIGNIN REACTED WITH SUPEROXIDE ANION RADICAL BY NMR SPECTROSCOPIES

Oxygen delignification can be considered to be the most important part of TCF and ECF bleaching sequences because it allows for cleaner production of pulp. During the process, oxygen gets one electron from lignin in the alkaline condition to form some active oxygen species (AOS), including a superoxide anion radical (O2-•), which is crucial for lignin degradation without damage of carbohydrates. The reaction of O2-• on cellulolytic enzymatic lignin (CEL) from Masson pine was studied. The change in active hydroxyl content after reaction with O2-• was investigated using 31P-NMR. After reaction, the aliphatic hydroxyl and uncondensed type phenol hydroxyl contents decreased, but the content of carboxylic group increased in Masson pine lignin. Through the analysis with HSQC-2D13C-H technology, β-O-4 linkages could be cleaved by O2-•, but β-β and β-5 linkages were observed to be more stable; benzaldehyde and cinnamic aldehyde structures could be oxidized to carboxylic acids by O2-•. Guaiacyl units in lignin were more easily degraded than p-hydroxybenzene units

A High Flux Electrochemical Filtration System Based on Electrospun Carbon Nanofiber Membrane for Efficient Tetracycline Degradation

In this work, an electrochemical filter using an electrospun carbon nanofiber membrane (ECNFM) anode fabricated by electrospinning, stabilization and carbonization was developed for the removal of antibiotic tetracycline (TC). ECNFM with 2.5 wt% terephthalic acid (PTA) carbonized at 1000 °C (ECNFM-2.5%-1000) exhibited higher tensile stress (0.75 MPa) and porosity (92.8%), more graphitic structures and lower electron transfer resistance (23.52 Ω). Under the optimal condition of applied voltage 2.0 V, pH 6.1, 0.1 mol L−1 Na2SO4, initial TC concentration 10 ppm and membrane flux 425 LMH, the TC removal efficiency of the electrochemical filter of ECNFM-2.5%-1000 reached 99.8%, and no obvious performance loss was observed after 8 h of continuous operation. The pseudo-first-order reaction rate constant in flow-through mode was 2.28 min−1, which was 10.53 times higher than that in batch mode. Meanwhile, the energy demand for 90% TC removal was only 0.017 kWh m−3. TC could be converted to intermediates with lower developmental toxicity and mutagenicity via the loss of functional groups (-CONH2, -CH3, -OH, -N(CH3)2) and ring opening reaction, which was mainly achieved by direct anodic oxidation. This study highlights the potential of ECNFM-based electrochemical filtration for efficient and economical drinking water purification

A High Flux Electrochemical Filtration System Based on Electrospun Carbon Nanofiber Membrane for Efficient Tetracycline Degradation

In this work, an electrochemical filter using an electrospun carbon nanofiber membrane (ECNFM) anode fabricated by electrospinning, stabilization and carbonization was developed for the removal of antibiotic tetracycline (TC). ECNFM with 2.5 wt% terephthalic acid (PTA) carbonized at 1000 °C (ECNFM-2.5%-1000) exhibited higher tensile stress (0.75 MPa) and porosity (92.8%), more graphitic structures and lower electron transfer resistance (23.52 Ω). Under the optimal condition of applied voltage 2.0 V, pH 6.1, 0.1 mol L−1 Na2SO4, initial TC concentration 10 ppm and membrane flux 425 LMH, the TC removal efficiency of the electrochemical filter of ECNFM-2.5%-1000 reached 99.8%, and no obvious performance loss was observed after 8 h of continuous operation. The pseudo-first-order reaction rate constant in flow-through mode was 2.28 min−1, which was 10.53 times higher than that in batch mode. Meanwhile, the energy demand for 90% TC removal was only 0.017 kWh m−3. TC could be converted to intermediates with lower developmental toxicity and mutagenicity via the loss of functional groups (-CONH2, -CH3, -OH, -N(CH3)2) and ring opening reaction, which was mainly achieved by direct anodic oxidation. This study highlights the potential of ECNFM-based electrochemical filtration for efficient and economical drinking water purification

Simultaneous removal of Ni(II) and fluoride from a real flue gas desulfurization wastewater by electrocoagulation using Fe/C/Al electrode

Large amounts of anions and heavy metals coexist in flue gas desulfurization (FGD) wastewater originating from coal-fired power plants, which cause serious environmental pollution. Electrocoagulation (EC) with Fe/C/Al hybrid electrodes was investigated for the separation of fluoride and nickel ions from a FGD wastewater. The study mainly focused on the technology parameters including anode electrode type, time, inter-electrode distance (5–40 mm), current density (1.88–6.25 mA/cm2) and initial pH (4–10). The results showed that favorable nickel and fluoride removal were obtained by increasing the time and current density, but this led to an increase in energy consumption. Eighty-six percent of fluoride and 98% of Ni(II) were removed by conducting the Fe/C/Al EC with a current density of 5.00 mA/cm2 and inter-electrode distance of 5 mm at pH 4 for 25 min and energy consumption was 1.33 kWh/m3. Concomitant pollutants also achieved excellent treatment efficiency. The Hg, Mn, Pb, Cd, Cu, SS and chemical oxygen demand were reduced by 90%, 89%, 92%, 88%, 98%, 99.9% and 89%, respectively, which met stringent environmental regulations

Preparation of the Essential Oil from Artemisia Argyi Grown in Qichun, China and its application in Antibacterial effection

To evaluate the antibacterial activity and chemical constituents of the essential oil from the artemisia argyi grown in Qichun (China). METHODS: Steam distillation method was used to extract volatile oil from Artemisia argyi. The antibacterial effect of the volatile oil was investigated by the plate coating method and the double gradient liquid dilution method. Gas chromatography-mass spectrometry(GC-MS) was applied for the identification of chemical constituents in volatile oil from Artemisia argyi and the relative percentage of each component was calculated by area normalization. RESULTS: The essential oil from artemisia argyi grown in Qichun (China) has significant antibacterial activity against staphylococcus aureus, pseudomonas aeruginosa, salmonella, candida albicans, aspergillus niger and aspergillus flavus. And fifty chemical components were detected in the essential oil, and twenty compounds were identified, accounting for 95.95% of total essential oil. And the artemisol in artemisia argyi grown in Qichun (China) was found to be the highest compared with the same species from other producing areas. CONCLUSION: The essential oil from artemisia argyi grown in Qichun (China) was a potent antibacterial plant extract with potential applications as an antibacterial drugs or food preservative

Cyclospora and Cyclosporiasis: The Nepalese Perspective

Cyclosporiasis is an emerging disease that is ubiquitous in humans and other animals worldwide. Cyclospora cayetanensis , which is distributed in the tropical and subtropical regions, and endemic in several developing countries, is the only species of Cyclospora resulting in cyclosporiasis in humans. The main objective of this review was to summarize the prevalence of Cyclospora in humans, animals, and environmental samples in Nepal. The overall prevalence of Cyclospora in humans has been reported to be 10.3% (3,785/36,570), including 3.6% (60/1,640) among HIV immunocompromised cases, 2.1% (210/9,733) among children, and 13.9% (3,515/25,197) in humans of all age categories, while the prevalence was calculated to be 2.9% (29/983) and 10.5% (9/85) in domestic and wild animals, respectively. The molecular characterization data on Cyclospora as related to Nepal is limited to a very few positive isolates from humans, dogs, chickens, and monkeys. Exposure to sewage water and contaminated fresh food items, and the presence of domestic animals appear to have been associated to an outbreak of Cyclospora in humans. Considering Cyclospora spp. as the etiologic agent for diarrhoea, a comprehensive, wider scale molecular epidemiologic study in humans, animals, and environmental samples is warranted to elucidate the exact distribution loci and probable outbreak of cyclosporiasis in Nepal