On the masking of signals on immunoblots by cellular proteins

Functional magnetic resonance imaging (fMRI) is capable of detecting task-induced blood oxygenation changes using susceptibility sensitive pulse sequences such as gradient-recalled echo-planar imaging (EPI). The local signal increases seen in the time course are believed to be due to an increase in oxygen delivery that is incommensurate with oxygen demands. To help isolate the sources of functional signal changes, the authors have incorporated various forms of diffusion weighting into EPI pulse sequences to characterize the apparent mobility of the functionally modulated protons. Results suggest that the majority of the functional signal at 1.5 T arises from protons that have apparent diffusion coefficients that are approximately four or five times higher than that of brain tissue. This implies that significant functional signal sources are either protons within the vascular space or protons from the perivascular space that is occupied by cerebrospinal fluid.     

Child health and the social environment of white and black children

Both poverty and other factors associated with race are related to child health. However, the mechanisms of these relationships have not been adequately specified. The purpose of this study was to explore the relationship of the social environment to child health status in black and white children and further, to explore whether the patterns of the effects of social class were different by race. This study provides further evidence that the social environment is strongly associated with child health status. Several risk factors are similar for both white and black children: mothers who view their own health as fair or poor are much more likely to rate their children in poor health. The presence of childhood chronic medical conditions is independently associated with poor health status regardless of race. However, the relative importance of several social risks for poor health status differs between white and black children. Specifically, while low family income is a consistent risk factor for poor health among white children, low income alone is not a risk factor for black children. Among black children, other social risks that are associated with poverty, such as low maternal education and a mother's perception of her own health as poor, increased the risk of poorer health in the child.     

Reciprocating flow ion exchange part II: Application to saline water softening

The “hardness” components in sea water can be considerably reduced by means of a new economical fixed bed technique called “Reciprocating Flow Ion Exchange”, when used in conjunction with a closed cycle exchanger-evaporator system. Removal of 87.9% of the calcium and 54.5% of the magnesium in sea water has been obtained with an overall flow rate of 5.0 U. S. g. p. m./sq. ft. Results from bench scale and a 5,000 g. p. d. pilot plant were identical. The virtually continuous cyclic steady-state process requires a small amount of exchanger (0.5 to 2% of the usual ion exchange methods, such as conventional fixed beds or fluidized beds). The effects of variation in operating parameters are discussed.     

Studies on effects of dietary fatty acids as related to their position on triglycerides

This article reviews published literature on how the stereospecific structure of dietary triglycerides may affect lipid metabolism in humans. Animal studies have shown enhanced absorption of fatty acids in the sn-2 position of dietary triglycerides. Increasing the level of the saturated fatty acid palmitic acid in the sn-2 position (e.g., by interesterification of the fat to randomize the positions of the fatty acids along the glycerol backbone) has been shown in rabbits to increase the atherogenic potential of the fat without impacting levels of blood lipids and lipoproteins. In contrast, enhancing the level of stearic acid in the sn-2 position has not been found to affect either atherogenic potential or levels of blood lipids and lipoproteins in rabbit. Fatty acids other than palmitic and stearic have not been studied systematically with respect to possible positional effects. A limited number of human studies have shown no significant effects of interesterified fats on blood lipid parameters. However, it is unknown whether modifying the stereospecific structure of dietary triglycerides would affect atherogenicity or other long-term health conditions in humans. It is possible that incorporation of palmitic acid into the sn-2 position of milk fat is beneficial to the human infant (as a source of energy for growth and development) but not to human adults. Additional research is needed to determine whether processes like interesterification, which can be used to alter physical parameters of dietary fats (e.g., melting characteristics), may result in favorable or unfavorable long-term effects in humans.     

Non-insulin-dependent diabetes: from physiopathology to treatment

Non-insulin-dependent (or type 2) diabetes mellitus is a common, underdiagnosed and growing disease in our society. It is responsible for increased morbidity and mortality and represents an important public health problem. This polygenic disease is often expressed late in life and its evolution is accelerated by environmental factors leading to obesity. It combines defects in both insulin secretion and insulin action, and such defects are present in various proportions according to the type of patient and the stage of the disease. Diet and physical activity recommendations are the basis of the treatment. Current pharmacological approaches aim at improving insulin secretion and/or insulin cellular action. After secondary failure to oral drugs, insulin therapy should be initiated, the patient becoming "insulin-requiring". A synergy should be searched in the combination of various therapeutic modalities in order to improve the glycaemic control.     

Low linolenate and commercial soybean oils diminish serum HDL cholesterol in young free-living adult females

OBJECTIVE: A mutant soybean line (A16) low in linolenic acid content (2% of oil by weight) was developed to increase oil oxidative stability. It was unknown whether serum lipid and lipoprotein concentrations in humans would be affected should A16 soybean oil (A16 oil) replace commercial soybean oil in diets. This study was conducted to examine the hypothesis that in free-living normolipidemic women, the consumption of A16 oil at approximately 10% of energy intake (en%) would not affect serum lipids and lipoproteins differently than would the consumption of the same amount of a commercial soybean oil with 7% of linolenic acid content. DESIGN: Fifteen free-living female college students consumed the soybean oil daily with regular meals for 9 weeks in different orders, with each test oil being eaten for 3 weeks. During the study, 13 en% was provided by each test oil and a total of 35 en% was from dietary fat. Serum concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL cholesterol), low-density lipoprotein cholesterol (LDL cholesterol) and triacylglycerides (TAG) were measured. Serum total fatty acid patterns were analyzed as well. RESULTS: Each of the three test oils decreased serum total cholesterol, LDL cholesterol and TAG concentrations from the baseline values. The feeding of A16 and commercial soybean oils decreased serum HDL cholesterol significantly compared with coconut oil (p < 0.05). Dietary inclusion of coconut oil increased serum myristic acid significantly more than did either soybean oil (p < 0.01). Serum arachidonic acid concentrations were significantly greater with A16 consumption than with commercial soybean oil consumption (p < 0.001). CONCLUSION: A16 and commercial soybean oils both diminished serum HDL cholesterol. Although the fatty acid composition differed between the two soybean oils, A16 oil and commercial oil had similar effects on serum concentrations of lipoproteins and lipids. With increased oxidative stability, A16 oil is a good alternative to commercial soybean oil.     

Weighted argument systems: Basic definitions, algorithms, and complexity results

We introduce and investigate a natural extension of Dung's well-known model of argument systems in which attacks are associated with a weight, indicating the relative strength of the attack. A key concept in our framework is the notion of an inconsistency budget, which characterises how much inconsistency we are prepared to tolerate: given an inconsistency budget β, we would be prepared to disregard attacks up to a total weight of β. The key advantage of this approach is that it permits a much finer grained level of analysis of argument systems than unweighted systems, and gives useful solutions when conventional (unweighted) argument systems have none. We begin by reviewing Dung's abstract argument systems, and motivating weights on attacks (as opposed to the alternative possibility, which is to attach weights to arguments). We then present the framework of weighted argument systems. We investigate solutions for weighted argument systems and the complexity of computing such solutions, focussing in particular on weighted variations of grounded extensions. Finally, we relate our work to the most relevant examples of argumentation frameworks that incorporate strengths.     

Self-consistent solutions for allowed interconnect current density.II. Application to design guidelines

We apply the newly developed approach for obtaining self-consistent solutions of the maximum allowed interconnect peak current density as a function of duty cycle, which simultaneously comprehends both electromigration and Joule heating. We demonstrate how to generalize this approach for arbitrary time-varying current density waveforms by introducing an effective duty cycle. We find that bipolar stressing is not always more optimistic than unipolar stressing, depending on the duty cycle. We illustrate worst-case intralevel interactions for multiple leads in a single-level metal system, and show that an effective duty cycle which depends on individual width ratios and duty cycles can be used to determine these worst-case solutions. We also study interlevel interactions in a multilevel metal system. Intralevel and interlevel interactions can cause marked reduction in the maximum allowed peak current density in a lead compared to an equivalent isolated lead, most strongly when its duty cycle is large and the duty cycles of the other interacting leads are small. Complexities due to waveshapes and interactions as described here, coupled with the complexities of real circuit layout and operation, motivate the need for sophisticated circuit simulators which can accurately determine electromigration reliability while self-consistently comprehending Joule heating