Toxic dinoflagellates (Alexandrium fundyense and A. catenella) have minimal apparent effects on oyster hemocytes

The possible effect of Alexandrium spp. containing paralytic shellfish poisoning (PSP) toxins on the hemocytes of oysters was tested experimentally. In one trial, eastern oysters, Crassostrea virginica Gmelin, were exposed to bloom concentrations of the sympatric dinoflagellate, Alexandrium fundyense Balech, alone and in a mixture with a non-toxic diatom, Thalassiosira weissflogii (Grun) Fryxell et Hasle. Subsequently, another experiment exposed Pacific oysters, Crassostrea gigas Thunberg, to a mixed suspension of the sympatric, toxic species Alexandrium catenella (Whedon et Kofoid) Balech, with T. weissflogii. Measurements of numbers of oyster hemocytes, percentages of different cell types, and functions (phagocytosis, reactive oxygen species (ROS) production, and mortality) were made using flow-cytometry. During and after exposure, almost no significant effects of Alexandrium spp. upon hemocyte numbers, morphology, or functions were detected, despite observations of adductor-muscle paralysis in C. virginica and measured toxin accumulation in C. gigas. The only significant correlation found was between toxin accumulation at one temperature and higher numbers of circulating live and dead hemocytes in C. gigas. The PSP toxins are known to interfere specifically with sodium-channel function; therefore, the finding that the toxins had no effect on measured hemocyte functions suggests that sodium-channel physiology is not important in these hemocyte functions. Finally, because oysters were exposed to the living algae, not purified toxins, there was no evidence of bioactive compounds other than PSP toxins affecting hemocytes in the two species of Alexandrium studied.     

Prenatal ultrasound diagnosis of rhizomelic chondrodysplasia punctata in a primigravida

Rhizomelic chondrodysplasia punctata (RCDP) is a sublethal autosomal recessive disorder characterized by skeletal dysplasia, microcephaly, mental retardation, congenital cataracts, joint contractures, skin changes, and failure to thrive. Prenatal ultrasound diagnosis has been reported during the second trimester of pregnancy. Prenatal diagnosis is also possible from the first trimester onwards by demonstration of peroxisomal dysfunction in cultured chorionic villous or amniotic fluid cells. In all cases reported hitherto, the prenatal diagnosis was established after the birth of a previous affected child. In contrast to these studies in pregnant multiparous women at risk for RCDP, we report on the first case of prenatal ultrasound diagnosis of RCDP at 19 weeks' gestation in a primigravida. In addition, a complex cardiac malformation associated with hypoplasia of the thymus (DiGeorge anomaly) is described.     

Operator-splitting procedures for reactive transport and comparison of mass balance errors

Operator-splitting (OS) techniques are very attractive for numerical modelling of reactive transport, but they induce some errors. Considering reactive mass transport with reversible and irreversible reactions governed by a first-order rate law, we develop analytical solutions of the mass balance for the following operator-splitting schemes: standard sequential non-iterative (SNI), Strang-splitting SNI, standard sequential iterative (SI), extrapolating SI, and symmetric SI approaches. From these analytical solutions, the operator-splitting methods are compared with respect to mass balance errors and convergence rates independently of the techniques used for solving each operator. Dimensionless times, NOS, are defined. They control mass balance errors and convergence rates. The following order in terms of decreasing efficiency is proposed: symmetric SI, Strang-splitting SNI, standard SNI, extrapolating SI and standard SI schemes. The symmetric SI scheme does not induce any operator-splitting errors, the Strang-splitting SNI appears to be O(N2OS) accurate, and the other schemes are first-order accurate.     

2006年碳市场发展状况与趋势分析(第1～3季度)

执行总结 碳市场总价值在2006年前三季度增长到215亿美元。比上年上涨一倍有余（见表格一）。全球碳市场主要以欧盟排放交易体系（EUETS）为主，且成功摆脱了由于2006年5月核证减排量数据公布而引起的交易价格下滑、市场疲软的局面。同时，基于项目的市场总值也在今年的前九个月增至24亿1000万美元。     

Prenatal overgrowth and mosaic trisomy 15q25-qter including the IGF1 receptor gene

Overgrowth is rarely associated with chromosomal imbalances. Here, we report on a male foetus presenting with overgrowth and additional material on the short arm of one of the chromosome 15 in 12% of lymphocytes and 50% of amniotic cells. Parents' karyotypes were normal, indicating a de novo origin for this unbalanced rearrangement. Complementary studies using cytogenetic and FISH studies showed that this additional material resulted in a 15q25-qter trisomy and confirmed the presence of three copies of the insulin-like growth factor 1 receptor (IGF1R) gene, included in the trisomic region. Autopsy performed after termination of pregnancy revealed isolated overgrowth and absence of visceral malformations. The possible mechanisms and origins for the formation of this mosaic pure trisomy are complex. The present observation emphasises the hypothesis that the overgrowth phenotype, frequently reported in patients with trisomy including the 15q26 region, might be causally related to a dosage effect of the IGF1R gene, as well as the importance of chromosome analysis in patients with overgrowth. It also confirms that the overgrowth is of prenatal onset in those observations. Copyright © 2004 John Wiley & Sons, Ltd.     

Magnetic molecularly imprinted polymer prepared by microwave heating for confirmatory determination of chloramphenicol in chicken feed using high-performance liquid chromatography-tandem mass spectrometry

Abstract

A magnetic molecularly imprinted polymer (MMIP) for chloramphenicol was prepared using a surface-imprinted and microwave-heating-induced polymerization method. The surfaces of the magnetic particles were first double-bond functionalized with 3-(trimethoxysilyl)propyl methacrylate (γ-MPS), followed by the copolymerization of 4-vinyl pyridine (4-VP) and trimethylolpropane trimethacrylate (TRIM) in the presence of chloramphenicol as a template and 1,1-azobis(cyclohexane-carbonitrile) (ABCN) as an initiator in a mixture of dimethyl sulfoxide and water with microwave heating at 80°C. The magnetic polymer possesses supraparamagnetic properties and was used to concentrate and cleanup chicken feed extract, followed by chromatographic separation using a Lichrospher®100 RP C8 column and detection with two multi-reaction monitoring transitions at m/z 321→ 152 and m/z 321→ 257. The mean recoveries obtained at two spiking levels were in the range of 94.6–100% The relative intra- and inter-day standard deviations were in the range of 1.4–2.6% and 5.1–5.7%, respectively. The detection limit of the method was 0.12 µg kg^?1. This confirmatory method was successfully applied to determine chloramphenicol in chicken feed samples.     

Insecticidal and antifungal chemicals produced by plants: a review

Leaf-cutting ants of the Attini tribe are a major pest of agricultural and forestry productions in the New World. Economic losses caused by these ants were estimated at several million dollars per year. These ants need to live in symbiosis with a basidiomycete fungus. Due to their mutualistic interaction with the symbiotic fungus, management of Attini ants can be done with insecticides or fungicides or both. So far, synthetic pesticides were the main control means, albeit with negative effects on the environment. Very few studies describe alternative methods for the control of leaf-cutting ants such as the use of insecticidal and fungicidal plant extracts. There is therefore a need of knowledge on phytochemicals and plants that could be used as insecticides and fungicides. Here, we review chemicals of plant origin and species with insecticidal and fungicidal activities. We establish a list of plants and phytochemicals that could manage leaf-cutting ants and also other insects, notably insects that use fungus-based agriculture. An exhaustive literature search of 1965 references from 1923 to 2010 was conducted using scientific databases, chemical databases, botanical databases, and books to identify published papers related to insecticidal and fungicidal chemical compounds stemmed from plant species. The major points are the following: (1) 119 and 284 chemicals have been cited in the literature for their insecticidal and fungicidal activities, respectively; (2) 656 and 1,064 plant species have significant insecticidal and fungicidal activities, respectively; (3) 3 main chemical classes were most cited for these activities: alkaloids, phenolics, and terpenoids; (4) 20 interesting chemicals with the both insecticidal and fungicidal activities were found; and (5) 305 plant species containing these chemicals were cited. To conclude, 20 chemicals: caryophyllene oxide, cinnamaldehyde, eugenol, helenalin, linalool, menthone, myristicin, pulegone, thymol, anethole, anisaldehyde, elemicin, isopimpinellin, plumbagin, podophyllotoxin, psoralen, xanthotoxin, anonaine, solamargine, and tomatine; two main plant families, Lamiaceae and Apiaceae; and 17 species of these families were particularly interesting for the management of leaf-cutting ants.     

Options for water storage and rainwater harvesting to improve health and resilience against climate change in Africa

West and East Africa experience high variability of rainfall that is expected to increase with climate change. This results in fluctuations in water availability for food production and other socioeconomic activities. Water harvesting and storage can mitigate the adverse effects of rainfall variability. But past studies have shown that when investments in water storage are not guided by environmental health considerations, the increased availability of open water surface may increase the transmission of water-related diseases. This is demonstrated for schistosomiasis associated with small reservoirs in Burkina Faso, and for malaria in Ethiopia around large dams, small dams, and water harvesting ponds. The concern is that the rush to develop water harvesting and storage for climate change adaptation may increase the risk for already vulnerable people, in some cases more than canceling out the benefits of greater water availability. Taking health issues into account in a participatory approach to planning, design, and management of rainwater harvesting and water storage, as well as considering the full range of water storage options would enable better opportunities for enhancing resilience against climate change in vulnerable populations in sub-Saharan Africa.