Scene oriented model for VBR video

A new model for variable bit rate (VBR) video traffic is presented. The model, which could be used as a traffic generator, considers two time scales: scenes, for periods of several minutes, and groups of pictures (GOP), for periods of half a second. To model the scene changes, a Markov chain is used. For the GOP level. A modification for the projected autoregressive (PAR) model is proposed so that the fitting of the autocorrelation function is improved. The model is used to imitate two real MPEG video signals, showing that it is able to accurately capture the behaviour of the real traffic in a queue     

Unusual fatty acid compositions of the hyperthermophilic archaeon Pyrococcus furiosus and the bacterium Thermotoga maritima

The fatty acid compositions of the hyperthermophilic microorganisms Thermotoga maritima and Pyrococcus furiosus were studied and compared. A total of 37 different fatty acids were identified in T. maritima, including the novel 13,14-dimethyloctacosanedioic acid. In contrast, a total of 18 different fatty acids were characterized, as minor components, in P. furiosus, and these included saturated, monounsaturated, and dicarboxylic acids. This is the first report of fatty acids from an archaeon.     

An InGaAs-InP HBT differential transimpedance amplifier with 47-GHz bandwidth

Return-to-zero differential phase-shift keying applications require a differential amplifier with high bandwidth, high gain, low noise, and good input impedance match. In this paper, we describe an InGaAs-InP heterostructure bipolar transistor differential transimpedance amplifier with high bandwidth of 47 GHz and high gain of 56 dB-/spl Omega/. The input-referred current noise is less than 35 pA//spl radic/Hz over the measurement range up to 40 GHz.     

Filipino personality structure and the big five model: a lexical approach

In lexically based studies, we derived Filipino personality dimensions and related them to the Big Five model. In Study 1, Filipino high-school and college students (N = 629) rated themselves on a near-comprehensive list of 861 Filipino (Tagalog) trait adjectives. In Study 2, Filipino high-school and college students (N = 1,531) rated 280 markers of dimensions identified in Study 1. Some students (n = 473) also completed the NEO Five-Factor Inventory. Seven comparable Filipino dimensions were identified in factor analyses in the two studies. We concluded that the dimensions we labeled Concern for Others (vs. Egotism), Conscientiousness, Gregariousness, and Intellect were quite similar to Big Five Agreeableness, Conscientiousness, Extraversion, and Intellect, respectively. The Filipino Self-Assurance dimension was most similar to Big Five Neuroticism. The Filipino Temperamentalness dimension was more complex in Big Five terms, overlapping Agreeableness, Conscientiousness, and Neuroticism. A final Filipino factor resembled a Negative Valence or Infrequency dimension. More than five factors had to be extracted to obtain Philippine dimensions resembling all of the Big Five.     

Small bowel cancer. Radiologic diagnosis

The diagnosis of small bowel cancer before it has metastasized continues to be a clinical and radiologic dilemma. This article presents an overview of the role of radiology in the diagnosis of small bowel cancer, describes techniques for optimal radiologic examination, and presents a pictorial essay of the radiologic features and differential diagnoses of these tumors.     

Quinolinic acid and lymphocyte subsets in the intrathecal compartment as biomarkers of SIV infection and simian AIDS

Cerebrospinal fluid (CSF) samples were collected from monkeys infected with SIVmac251 (SIV) or HIV-1/SIVmac chimeric viruses (SHIV(HXBc2) and SHIV(89.6P)) to investigate quinolinic acid (QUIN) levels in the intrathecal compartment. CSF levels of QUIN were elevated in the SIV-infected monkeys, especially in animals with end-stage disease, and in those infected with pathogenic SHIV(89.6P), but not after infection with the nonpathogenic construct SHIV(HXBc2). QUIN elevations occurred in association with reduced CD4+ and increased CD8+ lymphocytes, cellular alterations that were more pronounced in CSF than in the blood. These findings support the view that the intrathecal compartment provides a unique window on viral infection, and are in keeping with the a priori prediction that QUIN increases primarily in response to more pathogenic viral strains.     

QSAR model for ethylene polymerisation catalysed by supported bis(imino)pyridine iron complexes

We present a quantitative structure–activity relationship study performed over a set of bis(imino)pyridine iron catalyst used for olefin polymerisation. The experimental results were previously obtained by our research group. The structural variability of this catalyst set is mainly focused on the substituents of the aryl rings. We managed to find a statistically robust model which correlates the experimentally determined polymer's molecular weight with the steric and electrostatic fields. As a result the main contribution comes from the steric contribution which amounts up to 75% of the model. The predictive capability of the model was successfully probed with a test set of catalyst reported in the literature by other research group.     

Analysis of the Doppler signal (color and pulsed) in hepatocarcinoma

Real time echocardiography associated with pulsed Doppler (duplex) and color (triplex) provide a non invasive technique to determine the vascular morphology of a lesion. The duplex and triplex signal of 35 liver tumors, 23 hepatocarcinomas and 12 angiomas found in the first high frequency signals greater than 1.81 kHz and traced with pulsatile or mixed morphology (pulsed and continuous) were analyzed. The second signals were of low frequency, less than 1 kHz and continuous tracing. It may be concluded than echo-Doppler is a complementary technique to conventional echography and is useful in the diagnosis of hepatocellular carcinoma.     

Bifunctional Squaramide Catalysts with the Same Absolute Chirality for the Diastereodivergent Access to Densely Functionalised Cyclohexanes through Enantioselective Domino Reactions. Synthesis and Mechanistic Studies

We have developed a procedure for the stereoselective and diastereodivergent synthesis of densely functionalised cyclohexanes containing four stereocentres through an asymmetric Michael‐initiated ring closure (MIRC) cascade reaction employing hydrogen‐bond catalysis, which is able to prepare adducts with different absolute configurations starting from the same starting materials. The overall process involves a highly diastereo‐ and enantioselective Michael/Henry cascade reaction between a wide range of nitroalkenes and α‐nitro‐δ‐oxo esters, allowing access to different diastereoisomers of the final adduct by introducing subtle changes in the general (R,R)‐configured bifunctional tertiary amine/squaramide catalyst structure. Moreover, this methodology is also amenable to a three‐component one‐pot procedure, leading to the formation of the same adducts with very good results directly from commercially available reagents, on a multigram scale, and employing a very low catalyst loading. Furthermore, a detailed experimental and computational study is described which shows the origin of the diastereodivergent behaviour of these structurally similar catalysts and the nature of the substrate–catalyst interaction.

     

Detection of outliers in gas emissions from urban areas using functional data analysis

In this work a solution for the problem of the detection of outliers in gas emissions in urban areas that uses functional data analysis is described. Different methodologies for outlier identification have been applied in air pollution studies, with gas emissions considered as vectors whose components are gas concentration values for each observation made. In our methodology we consider gas emissions over time as curves, with outliers obtained by a comparison of curves instead of vectors. The methodology, which is based on the concept of functional depth, was applied to the detection of outliers in gas omissions in the city of Oviedo and results were compared with those obtained using a conventional method based on a comparison of vectors. Finally, the advantages of the functional method are reported.