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991.
The linearity of the interspecies relation between the elemental contents in Parmelia sulcata and Lecanora conizaeoides, sampled in a polluted area, was examined by the function y=az+b and yz –1=a+bz –1, with y and z being the elemental content in Parmelia and Lecanora, respectively. For As, Co, V and Zn significant positive a and b values were found, allowing interspecies calibration. For Br, Cd, Cr, Fe, La, Sb, Se and W the a values were zero and the b values were positive, indicating saturation of Parmelia and thus ruling out interspecies calibration. For Cu a part of the data set showed saturation effects in Lecanora. The results showed that the average concentration ratio could not be used for intercalibration purposes, because the concentration ratios were dependent on the concentrations.  相似文献   
992.
993.
We report a prenatal case of a maternally inherited abnormal chromosome 16, originally interpreted as a pericentric inversion only, but after family studies re-interpreted as a pericentric inversion (16) accompanied by an unbalanced (7;16) translocation. Because of the inversion 16 and an elder son with developmental delay and craniofacial dysmorphic features, in the past karyotyped as 46,XY, the chromosomes 16 of the mother and son were carefully re-examined. Using a whole chromosome 16 paint and sub-telomere probes of 16p and 16q, the karyotype of the mother was shown to be 46,XX,inv(16)(p11.2q23.2).ish t(7;16)(q36;p13.3)inv(16). Subsequently one chromosome 16 of the elder son appeared to be a der(16)t(7;16)(q36;p13.3). This is probably the result of a meiotic crossover between the chromosomes 16 in the mother. The prenatal karyotype was finally interpreted as 46,XY,inv(16)(p11.2q23.2).ish der(16)t(7;16)(q36;p13.3)inv(16). This is the same cytogenetic imbalance as his elder brother: a partial trisomy of chromosome 7 (q36→qter) and a partial monosomy of chromosome 16 (p13.3→pter). Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
994.

Objective

To develop a realistic simulation model for laparotomy-assisted fetoscopic spina bifida aperta (SBa) surgery, to be used for training purposes and preoperative planning.

Methods

The predefined general requirement was a realistic model of an exteriorized uterus, allowing all neurosurgical steps of the intervention. The uterus was modelled using ultrasound and MRI images of a 25 weeks’ gravid uterus, consisting of flexible polyurethane foam coated with pigmented silicone. The fetal model, contained an opening on the dorsal side for a customizable spinal insert with all the aspects of a SBa, including a cele, placode, and myofascial and skin layer. The model was assessed in a series of validation experiments.

Results

Production costs are low, uterus and fetus are reusable. Placental localization and the level and size of the spinal defect are adjustable, enabling case-specific adaptations. All aspects of the simulator were scored close to realistic or higher for both appearance and functional capacities.

Conclusions

This innovative model provides an excellent training opportunity for centers that are starting a fetoscopic SBa repair program. It is the first simulation model with adjustable spinal defect and placental localisation. Further objective validation is required, but the potential for using this model in preoperative planning is promising.  相似文献   
995.

Objective

To evaluate and compare the outcome of fetuses and neonates with congenital small bowel obstructions (SBO), evaluate the screening performance of prenatal ultrasound for SBO and identify possible risk factors for adverse outcomes.

Methods

All cases referred to the Amsterdam University Medical Centers between 2007 and 2021 for a prenatal suspected SBO, supplemented by cases of postnatal diagnosis of SBO, were included. The primary outcome was survival after 24 weeks of gestation until the first year of life.

Results

147 cases of SBO were included with a survival rate of 86.2% (119/138) after 24 weeks of gestation until the first year of age. Additional structural or chromosomal anomalies were found to have an increased risk of adverse outcomes. Intrauterine fetal demise occurred in 10/147 (6.8%) cases and 9/147 (6.1%) cases died during postnatal follow-up. The overall positive predictive value of all prenatally diagnosed cases was 91.5%. Surgical correction was performed in 123/128 (96.0%) of the live-born cases.

Conclusions

Congenital SBO has an overall favorable prognosis, but the outcome is negatively impacted by the possible presence of additional structural or chromosomal anomalies. Fetal monitoring in the early third trimester should be considered, since all cases of Intrauterine fetal demise occurred between 30 and 35 weeks of gestation.  相似文献   
996.
It has become increasingly clear that desertification can only be tackled through a multi-disciplinary approach that not only involves scientists but also stakeholders. In the DESIRE project such an approach was taken. As a first step, a conceptual framework was developed in which the factors and processes that may lead to land degradation and desertification were described. Many of these factors do not work independently, but can reinforce or weaken one another, and to illustrate these relationships sustainable management and policy feedback loops were included. This conceptual framework can be applied globally, but can also be made site-specific to take into account that each study site has a unique combination of bio-physical, socio-economic and political conditions. Once the conceptual framework was defined, a methodological framework was developed in which the methodological steps taken in the DESIRE approach were listed and their logic and sequence were explained. The last step was to develop a concrete working plan to put the project into action, involving stakeholders throughout the process. This series of steps, in full or in part, offers explicit guidance for other organizations or projects that aim to reduce land degradation and desertification.  相似文献   
997.
Urban living environments are known to influence human well-being and health; however, little is known about the multidimensionality of different environmental burdens. The aim of this study is to examine the relations between multiple burdens and self-rated health of city residents in Berlin. A spatial analysis was conducted to determine neighborhood street blocks with high versus low levels of three environmental burdens (traffic noise, air pollution, lack of public green space) as study sites for a cross-sectional household questionnaire. Burden level served as a dichotomous predictor to compare residents' self-reports of neighborhood satisfaction, life satisfaction, health behavior, and psychological and physical health symptoms. Residents from high-burden blocks appraised the environmental conditions more stressful, reported poorer health behavior and were less satisfied with their neighborhood than residents from low-burden blocks. However, they did not differ in regard to more general health symptoms. Three other burdens (behavior-related noise, litter and dirt in public space, lack of urban vegetation), which could not be varied objectively, were assessed by their perceived intensity. Regression analyses of the relations between the perceived levels of all six burdens and outcomes in the total sample revealed the following: Neighborhood satisfaction could be predicted from multiple stressors and resources that co-occur independently, while more general health symptoms were related only to perceived air pollution. The results have implications for both urban planning and public health.  相似文献   
998.
Environmental Science and Pollution Research - With the exponential number of published data on neonicotinoids and fipronil during the last decade, an updated review of literature has been...  相似文献   
999.
1000.
Intraspecific competition is a pervasive phenomenon with important ecological and evolutionary consequences, yet its effect in natural populations remains controversial. Although numerous studies suggest that in many cases populations across all organisms are limited by density-dependent processes, this conclusion often relies on correlative data. Here, using an experimental approach, we examined the effect of intraspecific competition on population regulation of the ant Aphaenogaster senilis. In this species females are philopatric while males disperse by flying over relatively long distances. All colonies were removed from 15 experimental plots, except for one focal colony in each plot, while 15 other plots remained unmanipulated. After the first reproductive season, nest density in the experimental plots returned to a level nonsignificantly different from that in the control plots, which was not expected if the populations were indeed regulated by density-independent phenomena. In both the control plots and the experimental plots colonies remained overdispersed throughout the experiment, suggesting colony mutual exclusion. Nests outside the plots rapidly extended their foraging span, but we did not detect any significant inward migration into the experimental plots. Experimental reduction in density did not significantly affect the focal colonies' biomass, measured just before the first reproductive season. However, the ratio of males to workers-pupae biomasses was smaller in experimental plots, suggesting that colonies there had redirected part of the resources normally allocated to male production to the production instead of new workers. Microsatellite analysis indicated that, after the reproductive season, many colonies in the experimental plots were headed by a young queen that was the mother of the brood but not of the old workers, indicating that reduction in colony density stimulated fission of the remaining colonies. Finally, at the end of the experiment, 14 months after experimental reduction in density, colonies that derived from fission were smaller in the experimental than in the control plots, suggesting that the former had undergone fission at a smaller size than in control plots, which presumably allowed them to colonize the emptied areas. We conclude that colonies adjust resource allocation and colony fission to the degree of intraspecific competition.  相似文献   
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