High-Fat Diet Aggravates Cerebral Infarct,Hemorrhagic Transformation and Neuroinflammation in a Mouse Stroke Model

Background: Stroke in context of type 2 diabetes (T2D) is associated with a poorer outcome than in non-diabetic conditions. We aimed at creating a new reproducible mouse model of stroke in impaired glucose tolerance conditions induced by high-fat diet. Methods: Adult C57BL6 mice were fed for 2 months with either normal diet (ND) or high-fat diet (HFD). We used a model of Middle Cerebral Artery Occlusion (MCAO) for 90 min. Oral Glucose Tolerance Test (OGTT) and Insulin Tolerance Test (ITT) were used to assess pre-diabetic status. Brain infarct volume, hemorrhagic transformation (HT) as well as systemic and cerebral inflammatory markers were evaluated. Results: HFD was associated with an increased body weight and glycemia following OGTT. The HFD group presented a significant increase in brain infarct volume (38.7 (IQR 30–46.7%) vs. 28.45 (IQR 21–30%); p = 0.016) and HT (HFD: 2 (IQR 1–5) vs. ND: 0 (IQR 0–1); p = 0.012) and higher levels of IL-6 and MCP-1 in infarcted hemisphere compared to the ND group. Conclusion: Two months of HFD in adult mice were sufficient to alter the lipid profile and the control of hyperglycemia. These metabolic perturbations were significantly associated with increased infarct volume and hemorrhagic complications.     

Tile-boundary artifact reduction using odd tile size and the low-pass first convention.

It is well known that tile-boundary artifacts occur in wavelet-based lossy image coding. However, until now, their cause has not been understood well. In this paper, we show that boundary artifacts are an inescapable consequence of the usual methods used to choose tile size and the type of symmetric extension employed in a wavelet-based image decomposition system. This paper presents a novel method for reducing these tile-boundary artifacts. The method employs odd tile sizes (2N + 1 samples) rather than the conventional even tile sizes (2N samples). It is shown that, for the same bit rate, an image compressed using an odd tile length low-pass first (OTLPF) convention has significantly less boundary artifacts than an image compressed using even tile sizes. The OTLPF convention can also be incorporated into the JPEG 2000 image compression algorithm using extensions defined in Part 2 of this standard.     

Memory scanning: Are fixed and varied sets scanned concurrently or successively?

Subjects were timed as they decided whether individually presented probe letters were or were not contained in pairs of memorized sets of one, two, or four letters. One set was fixed in advance of a block of trials, while the other varied from trial to trial. In Experiments 1 and 2, subjects responded positively if the probe was in either set and negatively otherwise; in Experiment 3 they made different responses to fixed-set, varied-set, and negative probes. In all three experiments, reaction time (RT) to varied-set probes depended more on the size of the varied set than of the fixed set, whereas RT to fixed-set and negative probes depended more on the size of the fixed set. These results were generally consistent with the hypothesis that scanning of the two sets was at least to some extent concurrent rather than successive, with the fixed set scanned more slowly than the varied set. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of penicillin on fatty acid synthesis and excretion inStreptococcus mutans BHT

Treatment of exponentially growing cultures ofStreptococcus mutans BHT with growth-inhibitory concentrations (0.2 μg/ml) of benzylpenicillin stimulates the incorporation of [2-¹⁴C] acetate into lipids excreted by the cells by as much as 69-fold, but does not change the amount of¹⁴C incorporated into intracellular lipids. At this concentration of penicillin cellular lysis does not occur. The radioactive label is incorporated exclusively into the fatty acid moieties of the glycerolipids. The increase in the radioactive content of the extracellular lipids reflects an actual net increase in the total fatty acid content as determined by a chemical assay. During a 4-hr incubation in the presence of penicillin, the extracellular fatty acid ester concentration (per mg cell dry weight) increases 1.5 fold, even though there is no growth or cellular lysis. No change is observed in the intracellular fatty acid ester content. An indication of the relative rate of fatty acid synthesis was most readily obtained by placingS. mutans BHT in a buffer containing¹⁴C-acetate. Under these nongrowing conditions free fatty acids are the only lipids labeled, a factor which simplifies the assay. The addition of glycerol to the buffer causes all of the nonesterified fatty acids to be incorporated into glycerolipid. The cells excrete much of the lipid whether glycerol is present or not. Addition of penicillin to the nongrowth supporting buffer system does not stimulate the incorporation of [¹⁴C]-acetate into fatty acids. However, if cells are exposed to penicillin in a growth-supporting medium and then are transferred to the nongrowing buffer system containing no penicillin, the previously exposed cells retain the ability to incorporate [¹⁴C]-acetate into fatty acid at a higher rate than untreated cells over a prolonged period of time. The stimulation of [¹⁴C]-acetate into fatty acids in this system parallels but is not dependent on the stimulation by penicillin of the incorporation of [¹⁴C]-glycerol into glycerolipid and lipoteichoic acid synthesis previously demonstrated by our laboratory. The material of this paper is part of a thesis to be submitted by J.L.B. in partial fulfillment of the requirements for the Ph.D. degree from the Department of Biochemistry, Temple University.     

Flocculation behavior of some cationic polyelectrolytes

The settling rates and adsorption isotherms produced by a variety of suites of cationic polyelectrolytes in 3% kaolin suspensions were measured. Settling rates increased with molar mass even for low-mass, high-charge polymers. The very high settling rates produced by cationic copolymers of acrylamide decreased as the charge density of the polymer used increased. Hydrolysis of unbuffered polymers occurred over time and produced large changes in the effectiveness of the polymers. This is attributed to conformational changes. © 1994 John Wiley & Sons, Inc.     

Sensitization of the startle reflex by footshock: Blockade by lesions of the central nucleus of the amygdala or its efferent pathway to the brainstem.

Bilateral electrolytic lesions of the central, but not the lateral, nucleus of the amgydala blocked shock sensitization of startle (the increase in startle produced by presentation of ten 0.6-mA footshocks in rapid succession). Lesions of the central nucleus also decreased reactivity to shock (jumping and flinching) during shock presentation. However, this decrease in reactivity cannot account for the blockade of shock sensitization, because when a higher shock intensity (1.0 mA) was used, producing equivalent reactivity to that of controls at 0.6 mA, central nucleus lesions still blocked shock sensitization. Moreover, lesions of the caudal part of the ventral amygdalofugal pathway, which carries central nucleus efferents to the startle reflex pathway, also blocked shock sensitization. It is hypothesized that shock activates the central nucleus of the amygdala, which increases startle through modulation of the startle pathway. Activation of the amygdala by shock may be the unconditioned response relevant for fear conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Substance use as a robust correlate of school outcome measures for ethnically diverse adolescents of Asian/Pacific Islander ancestry.

School psychologists are generally not provided with the knowledge and skills to address both educational and psychosocial issues of Asian American and Pacific Islander students. The present study is the first of its kind in examining 36 independent (i.e., demographic, social, cultural, psychological) variables in association with four school outcomes (i.e., grade point average, absences, suspensions, and school infractions) with a large sample of Caucasian, Filipino, Native Hawaiian, Japanese, mixed/non-Hawaiian, and "other" Hawai'i high school students (N = 2,833). Given the relatively unique sample in question and the sheer number of variables, an exploratory approach was utilized with the goal of determining the most robust independent variables, with the unique inclusion of Hawaiian cultural identification. A cross-validation technique was used, whereby stepwise regressions were performed for each of two cross-validation samples; only common variables were retained in a final stepwise model for each of the four school outcomes. The results indicated that, remarkably, substance use accounted for the most variance (i.e., 8.4% -16.1 %) in the four school measures. Further analyses detailed the relationship, including the finding that smoking cigarettes regularly, accounted for the most variance compared to the other five substance use items. Further research and implications of the findings are discussed, including the need for prevention and intervention programs that incorporate substance use as a component, both within and outside of school environments. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The Structure of Working Memory From 4 to 15 Years of Age.

The structure of working memory and its development across the childhood years were investigated in children 4-15 years of age. The children were given multiple assessments of each component of the A. D. Baddeley and G. Hitch (1974) working memory model. Broadly similar linear functions characterized performance on all measures as a function of age. From 6 years onward, a model consisting of 3 distinct but correlated factors corresponding to the working memory model provided a good fit to the data. The results indicate that the basic modular structure of working memory is present from 6 years of age and possibly earlier, with each component undergoing sizable expansion in functional capacity throughout the early and middle school years to adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Shared syntactic representations in bilinguals: Evidence for the role of word-order repetition.

Studies on syntactic priming strongly suggest that bilinguals can store a single integrated representation of constructions that are similar in both languages (e.g., Spanish and English passives; R. J. Hartsuiker, M. J. Pickering, & E. Veltkamp, 2004). However, they may store 2 separate representations of constructions that involve different word orders (e.g., German and English passives; H. Loebell & K. Bock, 2003). In 5 experiments, the authors investigated within- and between-languages priming of Dutch, English, and German relative clauses. The authors found priming within Dutch (Experiment 1) and within English as a 2nd language (Experiments 2 and 4). An important finding is that priming occurred from Dutch to German (Experiment 5), which both have verb-final relative clauses; but it did not occur between Dutch and English (Experiments 3 and 4), which differ in relative-clause word order. The results suggest that word-order repetition is needed for the construction of integrated syntactic representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)