Adrenomedullin gene expression in the rat heart is stimulated by acute pressure overload: blunted effect in experimental hypertension

The levels of adrenomedullin (ADM), a newly discovered vasodilating and natriuretic peptide, are elevated in plasma and ventricular myocardium in human congestive heart failure suggesting that cardiac synthesis may contribute to the plasma concentrations of ADM. To examine the time course of induction and mechanisms regulating cardiac ADM gene expression, we determined the effect of acute and short-term cardiac overload on ventricular ADM mRNA and immunoreactive ADM (ir-ADM) levels in conscious rats. Acute pressure overload was produced by infusion of arginine8-vasopressin (AVP, 0.05 microg/kg/min, i.v.) for 2 h into 12-week-old hypertensive TGR(mREN-2)27 rats and normotensive Sprague-Dawley (SD) rats. Hypertension and marked left ventricular hypertrophy were associated with 2.2-times higher ir-ADM levels in the left ventricular epicardial layer (178 +/- 36 vs. 81 +/- 23 fmol/g, P<0.05) and 2.6-times higher ir-ADM levels in the left ventricular endocardial layer (213 +/- 23 vs. 83 +/- 22 fmol/g, P<0.01). The infusion of AVP for 2 h in normotensive rats produced rapid increases in the levels of left ventricular ADM mRNA (epicardial layer: 1.6-fold, P<0.05) and ir-ADM (endocardial layer: from 83 +/- 22 to 140 +/- 12 fmol/g, P<0.05), whereas ventricular ADM mRNA and ir-ADM levels did not change significantly in hypertensive rats. Short-term cardiac overload, induced by administration of angiotensin II (33.3 microg/kg/h, s.c., osmotic minipumps) for two weeks in normotensive SD rats resulted in left ventricular hypertrophy (3.05 +/- 0.17 vs. 2.75 +/- 0.3 mg/g, P<0.05) and a 1.5-fold increase (P<0.05) in ventricular ADM mRNA levels. In conclusion, the present results show that pressure overload acutely stimulated ventricular ADM gene expression in conscious normotensive rats suggesting a potential beneficial role for endogenous ADM production in the heart against cardiac overload. Since pressure overload-induced increase in ADM synthesis was attenuated in hypertensive rats, alterations in the ADM system may contribute to the pathogenesis of hypertension in the TGR(mREN-2)27 rat.     

Major challenges in platform design for the Russian continental shelf

There are fascinating economical and technical challenges facing field developers in the Russian continental shelf. As far as production platforms and offshore terminal structures are concerned one has to find out how to build them so that attractive investment economics can be achieved. Controlling project risks and reducing key uncertainties are found to have significance in this respect. Different ice resistant offshore structures and their construction methods are illustrated in this paper. The cost structure and technical features of the production platform types are also discussed with special attention given to the Russian construction facilities and equipment. Extreme ice loads and ice induced vibrations still remain areas of some uncertainty in offshore platforms. An approach to solve complicated interaction cases involving extreme first year ridges and hummock fields is outlined. Means to control ice loads and vibrations are discussed.     

Evidence for cAMP-independent mechanisms mediating the effects of adrenomedullin, a new inotropic peptide

OBJECTIVE: To determine the relation of skeletal body build and obesity to blood pressure and the prevalence of hypertension. DESIGN: Cross-sectional data obtained from the baseline recruitment of the EPIC-Potsdam Study, which is part of the European Prospective Investigation into Cancer and Nutrition (EPIC). SUBJECTS: A total of 10,303 subjects (4387 men, aged 40-65 y and 5916 women, aged 35-65 y) were recruited between January 1995 and July 1996. MEASUREMENTS: Anthropometric measures included body mass index (BMI), waist-hip ratio (WHR) and metrik index (MIX) as a measure of body build that is derived from the relation of chest depth and breadth to body height. Systolic and diastolic blood pressure was obtained using automatic oscillometric devices. Hypertension was defined as blood pressure > or = 160/95 mmHg or current use of antihypertensive medication. Information on lifestyle factors were obtained by personal interview. STATISTICAL ANALYSIS: Logistic regression was used to define the association of categories of BMI, WHR, and MIX and the prevalence of hypertension. Odds ratios (ORs) of being hypertensive were estimated comparing the highest to the lowest quintile, adjusting for age, smoking status, alcohol intake level, educational attainment, physical activity categories, and each of the anthropometric variables. RESULTS: The simultaneously adjusted OR of being hypertensive, comparing the highest vs the lowest category, was for BMI 2.3 (95% confidence interval (CI) = 1.6-3.2) in men and 1.8 (95% CI = 1.4-2.5) in women, for WHR 1.8 (95% CI = 1.4-2.4) in men and 1.5 (95% CI = 1.2-2.0) in women, and for MIX (largest chest size vs lowest chest size relative to body height) 2.0 (95% CI = 1.4-2.8) in men and 2.2 (95% CI = 1.6-3.1) in women. CONCLUSION: In addition to measures of overall obesity (BMI) as well as central obesity (WHR), skeletal body build (MIX) was independently associated with the prevalence of hypertension. The biological mechanism relating MIX to hypertension, however, is still unclear and needs further exploration.     

Steady-state vibrations of offshore structures

Offshore structures subjected to the action of drifting ice floes may experience several kinds of interactions with the ice feature. This paper addresses the structural response to forces that arise when the ice floe fractures against a vertical structure. Special attention is paid to the steady-state vibrations which may arise at medium ice velocities. The paper describes a straightforward design procedure for the dynamic response of narrow structures. The applicability of simple design concepts is discussed in connection with the design problems of wide offshore structures. Reference is made to recent experimental findings to show that numerical models of dynamic ice-structure interaction provide a promising design tool for both quasi-static and dynamic response of wide offshore structures.Published in Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 24–27, August, 1994.     

Effect of Camelina sativa expeller cake on performance and meat quality of broilers

The experiment was conducted to measure the effects of Camelina sativa expeller on the performance of broiler chickens and on the sensory quality and fatty acid composition of broiler meat. One‐day‐old broiler chickens were randomly allocated to the three dietary treatments which lasted 37 days. Experimental diets contained 0, 5 or 10% C. sativa expeller. Feed and water were offered ad libitum. The birds were weighed at the beginning, at 14 days and at the end of the trial at 37 days. Feed intake was recorded between weighings. C. sativa expeller reduced the growth of the birds linearly (P < 0.001). It also depressed their feed intake and feed conversion ratio during the starter phase (1–14 days). C. sativa did not cause any significant enlargement of the thyroid gland, nor were any liver lesions observed. Feeding of C. sativa significantly (P < 0.001) increased the omega‐3 fatty acid level in broiler meat. This was mainly due to an increase in α‐linolenic acid (18:3, n‐3). Feeding did not seem to have any adverse effect on the sensory quality of broiler meat. Meat from female broilers produced by feeding 5% C. sativa in the diet was significantly (P = 0.02) more tender than meat produced by feeding 10% C. sativa. Copyright © 2007 Society of Chemical Industry     

The effect of dietary forage to concentrate ratio and forage type on milk fatty acid composition and milk fat globule size of lactating cows

We examined the effects of 2 grass silage-based diets differing in forage:concentrate (FC) ratio and those of a red clover silage-based diet on intake, milk production, ruminal fatty acid (FA) biohydrogenation, milk FA composition, and milk fat globule (MFG) size distribution. Ten multiparous Nordic Red cows received the following treatments: grass silage-based diets containing high (70:30, HG) or low (30:70, LG) FC ratio or a red clover silage-based diet with an FC ratio of 50:50 (RC) on a dry matter basis. Determinations of MFG were performed from fresh milk samples without addition of EDTA so the results of fat globules >1 µm in diameter are emphasized instead of the entire globule population. Lower FC ratio in grass silage-based diets increased milk production with no effect on daily fat yield, leading to 13% lower milk fat concentration. The effect of FC ratio on MFG size was moderate. It did not affect the volume-weighted diameter in grass silage-based diets, although LG lowered the volume-surface diameter of MFG in the size class >1 µm compared with HG. Compared with HG, feeding LG moderately decreased the biohydrogenation of 18:2n-6, leading to a higher level of polyunsaturated fatty acids in milk fat. Feeding RC lowered milk fat concentration and daily milk fat yield compared with grass silage-based diets. The volume-weighted diameter of MFG in the size class >1 µm was smaller in RC milk compared with grass silage-based diets. Feeding RC increased the flow of 18:3n-3 at the omasum by 2.4-fold and decreased the apparent ruminal 18:3n-3 biohydrogenation compared with grass silage-based diets despite similar intake of 18:3n-3. It also resulted in the lowest amount of saturated FA and the highest amounts of cis-9 18:1, 18:3n-3, and polyunsaturated FA in milk. In conclusion, LG decreased milk fat content and induced minor changes in MFG size distribution compared with HG, whereas RC lowered milk fat production, altered milk FA composition to nutritionally more beneficial direction, and led to smaller MFG compared with grass silage-based diets.     

Acceleration of the PDHGM on Partially Strongly Convex Functions

We propose several variants of the primal–dual method due to Chambolle and Pock. Without requiring full strong convexity of the objective functions, our methods are accelerated on subspaces with strong convexity. This yields mixed rates, \(O(1{/}N^2)\) with respect to initialisation and O(1 / N) with respect to the dual sequence, and the residual part of the primal sequence. We demonstrate the efficacy of the proposed methods on image processing problems lacking strong convexity, such as total generalised variation denoising and total variation deblurring.     

On principal component analysis, cosine and Euclidean measures in information retrieval

Clustering groups document objects represented as vectors. An extensive vector space may cause obstacles to applying these methods. Therefore, the vector space was reduced with principal component analysis (PCA). The conventional cosine measure is not the only choice with PCA, which involves the mean-correction of data. Since mean-correction changes the location of the origin, the angles between the document vectors also change. To avoid this, we used a connection between the cosine measure and the Euclidean distance in association with PCA, and grounded searching on the latter. We applied the single and complete linkage and Ward clustering to Finnish documents utilizing their relevance assessment as a new feature. After the normalization of the data PCA was run and relevant documents were clustered.     

Direct synthesis of carbon nanofibers on the surface of copper powder

A novel approach to synthesize carbon nanofibers (CNFs) directly on the surface of metal μm-sized particles to evenly disperse the carbon nanomaterials in a composite material was proposed. As a metal matrix, 5–10 μm copper particles were utilized. As a carbon source, C₂H₂, CH₄ and CO were examined. The best conditions were found to be in C₂H₂ (30 cm³/min) and H₂ (260 cm³/min) atmosphere at the temperature of 750 °C. The composites based on copper and CNFs prepared by vacuum hot pressing showed the increase in hardness from 35 to 60 kg/mm² almost retaining pure copper electrical properties.     

Analysis of Impedance and Noise Data of an X-Ray Transition-Edge Sensor Using Complex Thermal Models

The so-called excess noise limits the energy resolution of transition-edge sensor (TES) detectors, and its physical origin has been unclear, with many competing models proposed. Here we present the noise and impedance data analysis of a rectangular X-ray Ti/Au TES fabricated at SRON. To account for all the major features in the impedance and noise data simultaneously, we have used a thermal model consisting of three blocks of heat capacities, whereas a two-block model is clearly insufficient. The implication is that, for these detectors, the excess noise is simply thermal fluctuation noise of the internal parts of the device. Equations for the impedance and noise for a three-block model are also given.