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731.
732.
Abnormal ventral induction may result in disorders of formation, cleavage, and midline development of prosencephalic structures. Holoprosencephaly is a developmental field defect of impaired cleavage of prosencephalon. The most widely accepted classification of holoprosencephaly recognizes three major varieties: the alobar, semilobar and lobar types, according to the severity of the malformation. The brain malformations, characterized by the fusion of the cerebral hemisphere along the midline are commonly associated with facial anomalies. Corpus callosum agenesis and septo-optic dysplasia are disorders of prosencephalic midline development, and usually have less severe presentations but still, affected subjects may suffer from neurodevelopmental retardation, and/or endocrinologic and visual disorders. In this article we report an up-to-date of pathogenesis, prenatal sonographic findings, differential diagnosis and prognosis of the aforementioned anomalies. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
733.
The controversial family Adapisoriculidae, a group of shrew-sized Paleocene mammals, had proposed relationships with insectivores,
marsupials and more recently to plesiadapiforms. Adapisoriculid remains are numerous in the early Paleocene locality of Hainin,
Belgium, and allow us a test of these different phylogenetic hypotheses. Here, we identify the first tarsal bones of adapisoriculid
mammals. The highly specialised bones indicate an arboreal mode of life with euarchontan affinity. Moreover, the tarsal bones
are morphologically very close to those of the late Cretaceous Deccanolestes from the Deccan intertrappean beds of India, and also share several characters with the Paleocene plesiadapiforms and the
extant cynocephalid dermopterans. The adapisoriculid affinities of Deccanolestes are also confirmed by tooth morphology, indicating that Deccanolestes is a primitive member of this family. These phylogenetic affinities suggest a paleobiogeographic scenario for the family
with dispersal either via East Africa or across the Tethys area. 相似文献
734.
735.
The Lophogastrida are primitive Mysidacea and comprise only six genera. One of these, Eucopia is considered as highly specialized and constitutes the family Eucopiidae; the other genera constitute the Lophogastridae.
Among the latter family, the genus Gnathophausia is closely related to Eucopia, with two species (G. gracilis and E. sculpticauda) sharing similar morphological characteristics [i.e. ornamentation (spines) of the uropods, and the gastric mill]. This indicates
that these species are phylogenetically related. To test this hypothesis, the partial 16S mitochondrial ribosomal RNA gene
from various representative species of Gnathophausia and Eucopia were compared. The resulting phylogenetic tree suggests that each genus is monophyletic, and that Gnathophausia, which is the deepest-branching genus, is the most primitive, with the Eucopiidae originating from the Lophogastridae. The
molecular results support the morphological hypothesis, and suggest an early separation of the two genera or a rapid divergence
of Eucopia due to morphological specialization.
Received: 29 June 1997 / Accepted: 16 March 1998 相似文献
736.
Fernanda F. Heleno Maria Eliana L. R. de Queiroz Antônio Augusto Neves Romenique S. Freitas Lêda Rita A. Faroni André Fernando De Oliveira 《Journal of environmental science and health. Part. B》2013,48(2):94-101
The effect of ozone fumigation on the reduction of difenoconazole residue on strawberries was studied. Strawberries were immersed in 1.0 L of aqueous solution containing 400 μL of the commercial product (250 g L?1 of difenoconazole) for 1 min. Then, they were dried and exposed to ozone gas (O3) at concentrations of 0.3, 0.6 and 0.8 mg L?1 for 1 h. The ozone fumigation treatments reduced the difenoconazole residue on strawberries to concentrations below 0.5 mg kg?1, which corresponds to a 95% reduction. The strawberries treated with ozone and the control group, which was not treated with ozone, were stored at 4°C for 10 days. Some characteristics of the fruit were monitored throughout this period. Among these, pH, weight loss and total color difference did not change significantly (P > 0.05). The fumigation with ozone significantly affected the soluble solids, titratable acidity and ascorbic acid content (vitamin C) of the strawberries preventing a sharp reduction of these parameters during storage. 相似文献
737.
Carolina Lourencetti Mary R. R. De Marchi Maria L. Ribeiro 《Journal of environmental science and health. Part. B》2013,48(10):949-958
This study reports the influence of sugar cane vinasse on the persistence, sorption and leaching potential of diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea), hexazinone (3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4-dione) and tebuthiuron (1-(5-tert-butyl-1,3,4-thiadiazol-2-yl)-1,3-dimethylurea) in both a clay and sandy soil from a tropical area of Brazil. The experiments were conducted out under controlled laboratory conditions. The addition of sugarcane vinasse to soil influenced the persistence and sorption of the herbicides in both the studied clay and sandy soils, with a considerable decrease in the diuron DT50 values in clay soil. The Ground Water Ubiquity Score (GUS) Index classifies the herbicides as leachers in both soils and treatments, with the exception of diuron, which is classified as a non-leacher in clay soil-vinasse and as a transient herbicide in sandy soil. These results suggest that special attention should be given to areas such as those where the sandy soil was collected in this study, which is a recharge area of the Guarani Aquifer and is likely to experience groundwater contamination due to the high leaching potential of the applied pesticides. 相似文献
738.
Long-term sustainability of metal immobilization by soil amendments: Cyclonic ashes versus lime addition 总被引:4,自引:0,他引:4
A. Ruttens K. Adriaensen A. De Vocht R. Carleer J. Vangronsveld 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1428-1434
A soil column leaching experiment was used to gain insight into the long-term metal immobilization capacity of cyclonic ashes (CAH) compared to lime (LIME). Twenty six years of rainfall were simulated. Initially, all amended soils were brought to an equal soil pH. This was done to obtain optimal conditions for the detection of metal immobilization mechanisms different from just a pH effect. During the simulation period, soil pH in all treatments decreased in parallel. However, the evolution of metal mobility and phytoavailability showed a clearly distinct pattern. The strong reduction in metal immobilizing efficiency observed in the lime treatment at the end of the simulation period was much less pronounced, or even absent, in the CAH treatments. Moreover, metal accumulation in plants grown on the CAH amended soil was significantly lower compared to the untreated and the lime treated soil. CAH + SS treatment delivered the strongest reductions in metal mobility and bioavailability. 相似文献
739.
Pedro Simões Kristof De Witte Rui Cunha Marques 《Waste management (New York, N.Y.)》2010,30(6):1130-1137
This research computes the influence of the operational environment on the efficiency of the Portuguese urban solid waste services. A sample of 29 solid waste utilities encompassing the whole continental country was used for this purpose. Particularly, we apply the non-parametric double bootstrap model to estimate the effect of various explanatory factors on robust data envelopment analysis estimates. In general, we find a significant influence of the environmental context on the solid waste utilities’ performance. The environmental context is characterized by gross domestic product per capita, distance to treatment facilities, population density, regulation, type of management, composting and incineration services. 相似文献
740.
Dan D. Wang Kun M. Zheng Xiao Q. Li Yu P. Zhang De Y. Hu 《Journal of environmental science and health. Part. B》2013,48(12):793-801
AbstractThe aim of this investigation was to investigate the fate and translocation characteristics of saisenxin (SSX), a novel organic zinc fungicide, in the environment and tobacco plants under conventional field and laboratory conditions. A rapid and sensitive analytical technique based on high-performance liquid chromatography was used for determination of SSX, in soil samples and tobacco leaf, stem and root samples. The method had satisfactiry linearity (R2?=?0.9999) and the limits of detection and of quantitation of the target compound were 0.06 and 0.20?mg kg?1, respectively. The average recoveries were in the range of 89.74–94.24% in soil, leaf, stem and root samples, with relative standard deviations of <8%. For conventional field trials, the half-life (t1/2) of SSX was 5.9–6.5 days in soil and 4.8–5.3 days in tobacco leaves; the corresponding values under controlled laboratory conditions were extended to 7.1 and 7.6?days. The translocation factor (TF) values were in the range of 0–2.25 and 0–0.25 for foliage and root irrigation treatments, respectively. The TFs of SSX in tobacco indicated that tobacco had a high ability to transfer SSX upward. 相似文献