A possible regulatory role of squalene epoxidase in chinese hamster ovary cells

Growth of Chinese Hamster Ovary (CHO) cells in the presence of 20% lipid depleted serum (LDS) for only 2 hr results in an increase in the synthesis of [¹⁴C] sterols from [¹⁴C] mevalonate and from [¹⁴C] squalene compared with cells grown under normal growth conditions in the presence of 10% fetal calf serum (FCS). This enhanced sterol synthesis increases with time of exposure of the cells to LDS. However, exposing these cells for time periods up to 42.5 hr to a growth medium containing 20% LDS did not result in enhanced [¹⁴C] sterol synthesis from [¹⁴C] 2,3-oxidosqualene. Incubation of these cells with [¹⁴C] mevalonate resulted in the accumulation of [¹⁴C] squalene regardless of the presence of either LDS or FCS. These results suggest that squalene epoxidase is a regulatory enzyme in the cholesterol biosynthetic pathway in CHO. This research was supported by Grant 1426 from the Council for Tobacco Research-USA, Inc.     

Compact beam expander with linear gratings

Novel compact beam expanders that could be useful for applications such as providing light to flat panel displays are presented. They are based on a planar configuration in which three spatially linear gratings are recorded on one transparent substrate, so as to expand a narrow incoming beam in two dimensions. We present the design and recording procedures along with results, showing a relatively uniform intensity of the wide output beam. Such expanders can serve for illuminating flat panel displays.     

Protein turnover in the hypertrophying kidney

To establish whether altered proteolysis contributes to the increase in protein content in hypertrophying kidneys, we studied protein turnover in proximal renal tubules isolated from rats with three forms of renal hypertrophy, diabetes mellitus (DM), ammonium chloride-induced acidosis and compensatory renal growth (CRG). We found that in DM and in chronic acidosis the normal balance in protein turnover is altered due to attenuated proteolysis and accelerated protein synthesis. Together this favors an increase in kidney protein content. In contrast, in CRG, the increase in protein content is entirely due to increased protein synthesis. Thus, the changes in protein turnover leading to the net gain in kidney protein content in renal hypertrophy depends on the cause of hypertrophy.     

Respiratory motion of the heart from free breathing coronary angiograms

Respiratory motion compensation for cardiac imaging requires knowledge of the heart's motion and deformation during breathing. This paper presents a method for measuring the natural tidal respiratory motion of the heart from free breathing coronary angiograms. A three-dimensional (3-D) deformation field describing the cardiac and respiratory motion of the coronary arteries is recovered from a biplane acquisition. A cardiac respiratory parametric model is formulated and used to decompose the deformation field into cardiac and respiratory components. Angiograms from ten patients were analyzed. A 3-D translation motion model was sufficient for describing the motion of the heart in only two patients. For all patients, the heart translated caudally (mean, 4.9+/-1.9 mm; range, 2.4 to 8.0 mm) and underwent a cranio-dorsal rotation (mean, 1.5 degrees+/-0.9 degrees; range, 0.2 degrees to 3.5 degrees) during inspiration. In eight patients, the heart also translated anteriorly (mean, 1.3+/-1.8 mm; range, -0.4 to 5.1 mm) and rotated in a caudo-dextral direction (mean, 1.2 degrees+/-1.3 degrees; range, -1.9 degrees to 3.2 degrees).     

Orientated crystallization in drawn thermoplastic polyimide modified by carbon nanofibers

The solid state crystallization in drawn thermoplastic polyimide films is studied as a function of draw ratio (DR) under the effect of vapor grown carbon fiber nanoinclusions. The nucleating effect of the nanoinclusions coupled with the orientation effect of drawing generates a unique orientated layered lamellar structure, characteristic of smectic‐like mesophase. The degree of draw induced orientated crystallization increases with the content of nanoinclusions and with the DR, and is reflected in the mechanical behavior of the film. Generally, the Young's modulus and the yield point of the drawn crystalline films in the drawing direction are significantly higher compared with the noncrystalline counterparts. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers     

Personality differences in spontaneous personality inferences at encoding.

Examined the relationship between individual differences on a trait measure with behavioral correlates—a balanced authoritarianism (F) scale developed by D. Byrne (1974)—and the content of stimulus sentences and their related dispositional retrieval cues. Two sets of sentences were developed in pretesting with 33 undergraduates. In the 1st set, events suggested a consensual disposition for each sentence actor to either high-F (HF) or low-F (LF) Ss. In the 2nd set, events suggested a different consensual disposition to HF and LF Ss. 38 HF and 39 LF undergraduates then read both sets of sentences for a "memory study." Consensual dispositions and semantic associates to the actors were used to cue recall. For the 1st set, there was a significant interaction between S type, sentence type, and cue type. LF dispositions were more effective retrieval cues for LF than for HF Ss. Ss had little accurate awareness of having made trait inferences. No significant effects were found for HF cues alone or for the 2nd sentence set. Results indicate that HF and LF Ss differ in their spontaneous social inferences about others and have little awareness of making these inferences. Implications for integrating trait and cognitive approaches to personality are discussed. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antilipolytic actions of vanadate and insulin in rat adipocytes mediated by distinctly different mechanisms

Vanadate, which mimics the biological effects of insulin, also inhibits lipolysis in rat adipocytes. Here we demonstrate that the antilipolytic effect of vanadate differs from that of insulin at least by the five following criteria: 1) vanadate inhibits lipolysis mediated by high (supraphysiological) concentrations of catecholamines; 2) vanadate antagonizes (Bu)2cAMP-mediated lipolysis; 3) vanadate antagonizes isobutylmethylxanthine-dependent lipolysis, 4) vanadate inhibits lipolysis mediated by okadaic acid; and 5) wortmannin, which blocks the antilipolytic effect of insulin, fails to block vanadate-mediated antilipolysis. Vanadate does activate phosphoinositol 3-kinase, and wortmannin blocks this activation. Our working hypothesis assumes that all of the insulin-like effects of vanadate, including antilipolysis, are initiated by the inhibition of protein phosphotyrosine phosphatases (PTPases). Among documented PTPase inhibitors we found that VOSO4 (oxidation state +4), several organic vanadyl compounds (+4), zinc (Zn2+), tungstate (W), and molybdate (Mo) also had antilipolytic activity. The order of potency was vanadyl acetylacetonate > or = VOSO4 > or = NaVO3 > or = vanadyl-dipicolinate > Zn2+ > W > Mo, and it correlated better with the inhibition of adipose membranal-PTPases in cell-free experiments. We have concluded that the antilipolytic effect of vanadate is 1) mechanistically distinct from that of insulin, 2) independent of phosphoinositol 3-kinase activation, and 3) independent of the lipolytic cascade. We also strongly suggest that the antilipolytic effect of vanadate emanates from inhibiting adipose membranal, rather than cytosolic PTPases, and present preliminary data showing distinct differences in catalysis between these two PTPase categories. Overall, the study indicates that antilipolysis can be manifested via alternative, insulin-independent, signal-transducing pathways.     

Rethinking cities in the Middle East: political economy, planning, and the lived space

Urbanisation is an economic, political, and socio-cultural complexity, and so is its interaction with cityscapes. However, this truism rarely finds an expression in academic research. It is obvious that economic transitions would determine the quality and volume of the built environment. Municipal and state decision making further shape the nature of urban spaces, and socio-cultural transformations influence perceived notions of the lived space and, in turn, reshape the physical landscape itself. Nevertheless, research on cities in the Middle East and elsewhere remains fairly limited in scope, with little cross-discipline 'conversation' among scholars in different fields which attempts to account for such complexity. This is all the more surprising as life in cities has become, over the past half century or so, the most significant form of human collective dwelling; in the Middle East over half the population currently lives in urban settings and the numbers are forecast to grow in the future.1

This review article is the result of a dialogue between an architect and an economic historian in response to the foregoing. We have united in an attempt to offer a more integrative approach to Middle East urbanism, accounting for the interactions of the political economy of this region, planning, and the lived space. The key questions on which we focus are why and how do state transformation and economic structural change impact upon urban space. In seeking the answers we examine the long-term trajectory of cities as they went through the first period of globalisation under imperial intervention and/or direct colonial rule; gradually came under independent, inward-looking, national regimes; and presently experience the second wave of globalisation and the opening of local economies to international markets. Such a narrative explores common themes in the historical trajectories of cities' lives.

Our long-term, geographically extensive overview (Map 1) is bound to miss some specific developments that have made a significant impact on the transformations of cities in the region; our aim is not to totalise Middle East experiences and reduce a variety of narratives to a simplistic linear model of change. Even more so, our study of the Middle East is mostly focused on Egypt, the Asian Arab countries (the mashraq), Israel/Palestine, and Turkey, the geographical unit which roughly corresponded with the Ottoman Empire, the last state to control the Middle East before the age of nations. We acknowledge that any bird's eye view perspective is bound to do some injustice to historically specific contexts, and city transitions that occurred in such contexts. We would welcome any future work that brings our suggestion here, namely to integrate political economy with the study of urban development and city life, to bear on more specific research on urbanism in the Middle East.     

Spectrophotometric method for determination of ozone in aqueous solutions

A sensitive spectrophotometric method for determination of ozone in small volumes of water is presented. It was performed in order to meet the requirements of a kinetic study of virus and bacteria inactivation by ozone.The proposed method involves oxidation of a buffered iodine solution and spectrophotometric measurement of the triiodide ion liberated by ozone. Two procedures are used: one for low ozone concentration (0·01–0·30 ppm) and another for higher concentrations (0·30–2·0 ppm). The reproducibility of results is very high when the procedure used corresponds with the ozone level for which it is intended.This spectrophotometric method is compared with the standard volumetric method and the differences are presented and discussed.Some applications of the method for a kinetic study of virus inactivation by ozone are presented.