Coordinate regulation of transcription and splicing by steroid receptor coregulators     

Auboeuf D  Hönig A  Berget SM  O'Malley BW 《Science (New York, N.Y.)》2002,298(5592):416-419

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Capillary wrinkling of floating thin polymer films     

Huang J  Juszkiewicz M  de Jeu WH  Cerda E  Emrick T  Menon N  Russell TP 《Science (New York, N.Y.)》2007,317(5838):650-653

A freely floating polymer film, tens of nanometers in thickness, wrinkles under the capillary force exerted by a drop of water placed on its surface. The wrinkling pattern is characterized by the number and length of the wrinkles. The dependence of the number of wrinkles on the elastic properties of the film and on the capillary force exerted by the drop confirms recent theoretical predictions on the selection of a pattern with a well-defined length scale in the wrinkling instability. We combined scaling relations that were developed for the length of the wrinkles with those for the number of wrinkles to construct a metrology for measuring the elasticity and thickness of ultrathin films that relies on no more than a dish of fluid and a low-magnification microscope. We validated this method on polymer films modified by plasticizer. The relaxation of the wrinkles affords a simple method to study the viscoelastic response of ultrathin films.  相似文献   

Differences between tight and loose cultures: a 33-nation study     

Gelfand MJ  Raver JL  Nishii L  Leslie LM  Lun J  Lim BC  Duan L  Almaliach A  Ang S  Arnadottir J  Aycan Z  Boehnke K  Boski P  Cabecinhas R  Chan D  Chhokar J  D'Amato A  Ferrer M  Fischlmayr IC  Fischer R  Fülöp M  Georgas J  Kashima ES  Kashima Y  Kim K  Lempereur A  Marquez P  Othman R  Overlaet B  Panagiotopoulou P  Peltzer K  Perez-Florizno LR  Ponomarenko L  Realo A  Schei V  Schmitt M  Smith PB  Soomro N  Szabo E  Taveesin N  Toyama M  Van de Vliert E  Vohra N  Ward C  Yamaguchi S 《Science (New York, N.Y.)》2011,332(6033):1100-1104

With data from 33 nations, we illustrate the differences between cultures that are tight (have many strong norms and a low tolerance of deviant behavior) versus loose (have weak social norms and a high tolerance of deviant behavior). Tightness-looseness is part of a complex, loosely integrated multilevel system that comprises distal ecological and historical threats (e.g., high population density, resource scarcity, a history of territorial conflict, and disease and environmental threats), broad versus narrow socialization in societal institutions (e.g., autocracy, media regulations), the strength of everyday recurring situations, and micro-level psychological affordances (e.g., prevention self-guides, high regulatory strength, need for structure). This research advances knowledge that can foster cross-cultural understanding in a world of increasing global interdependence and has implications for modeling cultural change.  相似文献   

Flow-microcalorimetry measurements of aerobic and anaerobic soil microbial activity     

Bert P. Albers  Friedrich Beese  Anton Hartmann 《Biology and Fertility of Soils》1995,19(2-3):203-208

Heat output can be used as an indicator of microbial activity and is usually measured in a microcalorimeter with closed ampoules. In long-term experiments particularly, interpretation of the data is hindered by the changing environment in the closed ampoules because of O₂ consumption and CO₂ enrichment. We used a combination of a flow-microcalorimeter and a gas chromatograph to measure the heat flux and CO₂ and N₂O production rates under controlled conditions. Simultaneous detection of the heat output and CO₂ emission allowed calculation of the calorimetric: CO₂ (Cal/CO₂) ratio. A mean ratio of-435 kJ mol^-1 CO₂ was detected in six different soils amended with glucose and incubated under aerobic conditions. This ratio indicated that CO₂ was the end-product of catabolism. In wet 10–12 mm soil aggregates of a gleyic vertisol amended with glucose, values of-285 kJ mol^-1 CO₂ under an aerobic and-141 kJ mol^-1 CO₂ under a N₂ atmosphere was determined. These findings indicated that fermentative metabolism occurred. The Cal/CO₂ ratio was not affected when enough NO _inf3 ^sup- was available and denitrification processes (N₂O production) were possible.  相似文献   

Effects of different management practices on the soil–water balance and crop yield for improved dryland farming in the Chinese Loess Plateau     

Ke Jin  Wim M. Cornelis  Wouter Schiettecatte  Junjie Lu  Yuqing Yao  Huijun Wu  Donald Gabriels  Stefaan De Neve  Dianxiong Cai  Jiyun Jin  Roger Hartmann 《Soil & Tillage Research》2007,96(1-2):131-144

Field experiments were carried out to study the effects of different soil management practices on the water balance, precipitation use efficiency (PUE), and crop yield (i.e. winter wheat and peanut) on a loess soil near Luoyang (east edge of the Chinese Loess Plateau, Henan Province, China). Field plots were set up in 1999 including following soil management practices: subsoiling with mulch (SS), no-till with mulch (NT), reduced tillage (RT), two crops per year (i.e. winter wheat and peanut, TC), and a conventional tillage control (CT). The field plots were equipped to monitor all components of the soil–water balance except evapotranspiration, which was computed by solving the water balance equation. The results showed that although soil management had smaller influence on the magnitude of the water balance components than did precipitation variations, small influences of the applied soil management practices on water conservation during the fallow period can greatly affect winter wheat yield. SS increased consistently precipitation storage efficiency (PSE) and PUE over the 5 years compared to CT except during the wettest year. NT also had a noticeable effect on postharvest water storage during the fallow period; however, the influence on yield of NT depended on the amount of precipitation. TC lowered the winter wheat yield mainly due to the unfavorable soil moisture conditions after growing peanut in summer; however, the harvested peanut gained an extra profit for the local farmer. No matter which kind of soil management practices was adapted, PSE never exceeded 41.6%, which was primarily attributed to high evapotranspiration. From data of five consecutive agricultural years between 2000 and 2005, it could be concluded that SS resulted in the highest PSE, PUE and crop yield. TC also showed promising results considering the economic value of the second crop. NT performed slightly less as SS. CT gave intermediate results, whereas RT was the worst alternative.  相似文献   

Sediments in the Catchment-coast Continuum (7 pp)     

Wim Salomons 《Journal of Soils and Sediments》2005,5(1):2-8

-  Dedicated to Prof. Dr. Ulrich Förstner on his 65th birthdayBackground   Sediments pose problems at their deposition sites when there is too little sediment (e.g. wetlands) or too much sediment (e.g. navigable waterways) and, additionally, when they are contaminated. These problems often have their origin upstream in the river catchment. Objective   Global aspects of changes concerning sediment quantity and quality, as they affect downstream areas, are reviewed. A case study of estuarine sediments demonstrates how a holistic approach helps in understanding and predicting their present and future quality. Results and Conclusions   Globally, large reservoirs intercept between 25 and 30% of the sediment and consequently supply the coast with impacts on wetlands and coastal morphology. In estuaries, the composition of sediments is determined by the mixing of marine sediments supplied from the coast and the supply by rivers. Natural tracers can be used to predict mixing ratios of marine to fluvial sediments in estuaries, and hence their contamination. Scenarios on implementation of pollution abatement, the implementation of regulations as well as climate change are needed to predict future sediment quality in downstream areas. The results show, even for a ‘green’ scenario, that sediment quality in the Rhine catchment will pose future problems due to the temporal storage of contaminants in soils and sediments.Recommendations and Outlook   The current methods applied make use of existing models linking sediment transport with point and diffuse sources in the river catchments and scenarios on the development of strength of point and diffuse sources. However, more effort is needed to come to a uniform framework which includes land use changes and links with more advanced scenario methodology for long to medium-term management of sediment quality and quantity in river catchments.  相似文献   

Comparison of measured and simulated changes in base cation amounts using a one-layer and a multi-layer soil acidification model     

Harmke Van Oene  Wim De Vries 《Water, air, and soil pollution》1994,72(1-4):41-65

Biogeochemical processes describing nutrient cycling strongly affect the development of different soil horizons and soil acidification. However, in many soil acidification models these processes are not directly simulated, and spatially distributed soil properties are lumped into average values. This paper describes the extension of a one-layer soil acidification model (SMART) to a multi-layer model (SMARTEX) by including nutrient cycling, and the performance of both models regarding their ability for the assessment of the effects of acid deposition on forest soil. This was done by comparing simulation results of the two models with respect to changes in base cation amounts to historical data from sites in south Sweden. The results showed that the multi-layer model gives better results for the top soil, whereas the one-layer model gives better results for the rootzone and the total profile. Since the top soil is most important, the extended model is more suited to relate acid deposition to forest growth than the more general results of the one-layer model. However, the sensitivity of the multi-layer model to some parameters is large. A change in these parameters had strong effects on the separate layers, whereas the effects were cancelled out over the total profile. This sensitivity requires a careful parameterization of the model which might be troublesome to lack of data.  相似文献   

A regional scale model for the calculation of episodic concentrations and depositions of acidifying components     

H. Jetske van Rheineck Leyssius  Frank A. A. M. de Leeuw  Bert H. Kesseboom 《Water, air, and soil pollution》1990,51(3-4):327-344

An eulerian long-range transport model for the calculation of concentrations of SO₂, SO₄, NO _x , and NO₃ and wet and dry depositions of SO _x (sum of SO₂ and SO₄) and NO _y (sum of NO, NO₂ and NO₃) over Europe is presented. The model is developed in such a way that only routinely available, analyzed or prognostic meteorological fields are required as input data. In this way it is possible to obtain a forecast of the air quality during smog episodes. For evaluation of smog episodes the model provides a way to estimate the contributions of different sources and the effect of emission scenarios. The model has been evaluated for four winter and three summer episodes. The modeled concentrations of SO₂ and SO, are in agreement with the available measurements. A less good agreement is found for NO₂ and NO _x (sum of NO and NO₂) concentrations. For these components the model tends to underpredict the measured values.  相似文献   

Gynogen Production in Hybrid Striped Bass     

Gilles M.  Leclerc  Bert  Ely  Xiao Lan  Xu Reginal M.  Harrell 《Journal of the World Aquaculture Society》1996,27(1):119-124

Abstract.— Meiotic gynogens were produced using hybrid striped bass (♀ white bass, Morone chrysops , ×♂ striped bass, M. saxatilis ) eggs and white perch M. americana UV-irradiated sperm. Diploidy of the fertilized eggs was restored by application of hydrostatic pressure, which induced retention of the second polar body. Use of white perch sperm provided an unmistakable marker for detection of a paternal genetic contribution. Two assays were developed using the polymerase chain reaction (PCR) to amplify specific regions of the Morone genome . Primers for gene amplification were developed based on the DNA sequence of the striped bass growth hormone gene (SB-GH) or an anonymous striped bass locus (SBI-10). Control experiments using DNA from the three Morone species demonstrated that gene amplification yielded species-specific patterns of DNA fragments for both of these loci. Therefore, any progeny with a paternal contribution of a set of white perch chromosomes could be identified. Using these assays, we demonstrated that greater than 75% of the progeny obtained from successful experiments were true gynogens. These striped bass hybrid gynogens will provide the basis for future efforts to calculate gene-centromere distances and to identify markers linked to specific traits of interest to aquaculture.  相似文献   

Legal regulations and practical application of studies of slaughtered game animals and their meat     

R M Hadlok  F Bert 《Tier?rztliche Praxis》1989,17(4):347-351

Meat regulations also involve game inspection. The previous publications on the one hand dealt with the regulations and their practice concerning game intended for slaughter, especially the control of fences and the gaining of meat. On the other hand regulations concerning game hunted for food (Deer: Red deer, Sika deer, Fallow deer, Roe deer; Horned ungulates: European mouflon, Chamois; Wild boar; European hare; European rabbit; game such as Badger and Raccoon) and regulations to be observed by hunters, mainly for the gaining of meat were discussed. The recent publication regarded meat inspection (routine inspection) of slaughter game. The following publication deals with meat inspection (routine inspection) of game hunted for food and with meat inspection (additional inspection) of slaughtered game as well as game hunted for food.  相似文献