Effect of 17 alpha-ethinylestradiol on the activity of enzymes synthesizing and hydrolyzing cholesterol esters in the rat liver

Intraperitoneal injection of 25 micrograms/100 g body weight of 17 alpha-ethinyl estradiol to rats was shown to decrease serum cholesterol and to increase hepatic cholesterol. The rise in the level of non-labeled and C14-labeled free and esterified cholesterol in hepatic homogenate, as well as in lysosomal and cytosol fractions was accompanied by reduced activity of acyl-CoA-cholesterol acyltransferase and increased activity of lysosomal cholesterol esterase, as compared with the controls. The activity of cytoplasmic cholesterol esterase remained practically unchanged. Fistula bile of treated rats collected during 30 min was analyzed for the concentration of free cholesterol and bile acids. It has been shown that treatment of rats with 17 alpha-ethinyl estradiol caused an increase in hepatic cholesterol elimination via bile pathways.     

On the Feasibility of a Coulomb Explosion in a Micropinch

Plasma Physics Reports - In this paper we present experimental data on the generation of ions with MeV-energy in a Z-pinch discharge in a heavy-element medium. The calculations show that the escape...     

The rise of a marine generalist predator and the fall of beta diversity

Determining the importance of physical and biological drivers in shaping biodiversity in diverse ecosystems remains a global challenge. Advancements have been made towards this end in large marine ecosystems with several studies suggesting environmental forcing as the primary driver. However, both empirical and theoretical studies point to additional drivers of changes in diversity involving trophic interactions and, in particular, predation. Moreover, a more integrated but less common approach to the assessment of biodiversity changes involves analyses of spatial β diversity, whereas most studies to date assess only changes in species richness (α diversity). Recent research has established that when cod, a dominant generalist predator, was overfished and collapsed in a northwest Atlantic food web, spatial β diversity increased; that is, the spatial structure of the fish assemblage became increasingly heterogeneous. If cod were to recover, would this situation be reversible, given the inherent complexity and non‐linear dynamics that typify such systems? A dramatic increase of cod in an ecologically similar large marine ecosystem may provide an answer. Here we show that spatial β diversity of fish assemblages in the Barents Sea decreased with increasing cod abundance, while decadal scale changes in temperature did not play a significant role. These findings indicate a reversibility of the fish assemblage structure in response to changing levels of an apex predator and highlight the frequently overlooked importance of trophic interactions in determining large‐scale biodiversity patterns. As increased cod abundance was largely driven by changes in fisheries management, our study also shows that management policies and practices, particularly those involving apex predators, can have a strong effect in shaping spatial diversity patterns, and one should not restrict the focus to effects of climate change alone.     

Effect of long-term restraint stress on behavior of female C57BL/6J and CBA/Lac inbred mice. Dispersion and cluster analysis]

An augmented exploratory behaviour and motor activity and diminished anxiety after a restraint stress were found in CBA/Lac female mice [corrected] but not in C57BL/6J ones. In the Porsolt test the result was exactly opposite. A possibility of inherent anxiety-depressive pathological condition in the C57BL/6J mice [corrected] developing under the effect of repeated psychological stress, is assumed.     

Transgenic tomato plants as supersweet protein thaumatin II producers

Yalf tomato plants have been transformed with a gene for thaumatin II from Thaumatococcus daniellii Benth. The nucleotide sequence for thaumatin II cDNA was cloned in the pBI121 vector under the control of the CaMV 35S promoter of cauliflower mosaic virus. Expression of the thaumatin II gene was detected in all of the studied transgenic lines. A quantitative estimation of the thaumatin II accumulation in fruits was performed by ELISA. The highest content of thaumatin in transgenic tomato fruits (line 91) was 46.4 ± 10.5 μg/mg of total soluble protein (4.6%). In the other studied lines, the thaumatin content ranged from 17.6 ± 6.1 to 41.3 ± 12.3 μg/mg of total soluble protein (1.8–4.1%). The fruits of transgenic plants had a well-defined sweet taste with a long aftertaste typical of thaumatin II. Transgenic tomato lines with high expression levels can be potentially used as producers of thaumatin for the food and pharmaceutical industries.     

Resource‐driven colonization by cod in a high Arctic food web

1. Climate change is commonly associated with many species redistributions and the influence of other factors may be marginalized, especially in the rapidly warming Arctic.
2. The Barents Sea, a high latitude large marine ecosystem in the Northeast Atlantic has experienced above‐average temperatures since the mid‐2000s with divergent bottom temperature trends at subregional scales.
3. Concurrently, the Barents Sea stock of Atlantic cod Gadus morhua, one of the most important commercial fish stocks in the world, increased following a large reduction in fishing pressure and expanded north of 80°N.
4. We examined the influence of food availability and temperature on cod expansion using a comprehensive data set on cod stomach fullness stratified by subregions characterized by divergent temperature trends. We then tested whether food availability, as indexed by cod stomach fullness, played a role in cod expansion in subregions that were warming, cooling, or showed no trend.
5. The greatest increase in cod occupancy occurred in three northern subregions with contrasting temperature trends. Cod apparently benefited from initial high food availability in these regions that previously had few large‐bodied fish predators.
6. The stomach fullness in the northern subregions declined rapidly after a few years of high cod abundance, suggesting that the arrival of cod caused a top‐down effect on the prey base. Prolonged cod residency in the northern Barents Sea is, therefore, not a certainty.