H @ -Robustness properties preservation in SISO systems when applying SPR substitutions

The preservation of both robust stability and weighted robust performance properties of controlled linear time-invariant single input single output (SISO) systems is studied, when performing substitutions (of the complex Laplace variable s ) by a particular class of rational strictly positive real functions ( SPR functions), the so-called strictly positive real functions of zero relative degree ( SPR0 functions). Concerning weighted robust performance and model-matching, we provide some results on preservation of controller optimality.     

Correlation between DNA synthesis in the second, third and fourth generations of spermatogonia and the occurrence of apoptosis in both spermatogonia and spermatocytes

In the seminiferous epithelium, both DNA synthesis and apoptosis occur at equivalent stages in various species, with apoptosis taking place mainly at the same stages as DNA replication in the second, third and fourth spermatogonial generations. As preservation of the cellular associations found at these stages may have some functional significance, it is important to determine whether there is a correlation between these cellular events. In this study, pairs of immunoperoxidase-stained adjacent testis sections from rats, mice, rabbits and cats in which either bromodeoxyuridine incorporated into the newly synthesized DNA strand (BrdU labelling) or DNA 3' end labelling of the apoptotic DNA fragments (TUNEL assay) were detected were compared. In addition, both events were analysed in double-labelled sections. These two methods revealed a clear correlation between the occurrence of DNA replication in the second to fourth generations of spermatogonia and most physiological apoptosis taking place in both spermatogonia and spermatocytes in the three different mammalian orders (Rodentia, Lagomorpha and Carnivora). This correlation may result from the synchronization of mitotic spermatogonial and meiotic spermatocyte cell cycle checkpoints operating at these stages.     

Synthesis of an Al-ZrO2 composite by infiltration of Zr-chelates into an Al matrix

Aluminium-based matrix composites were prepared by infiltration with an ammoniacal zirconium chelate within an Al matrix synthesized via Aluminium powder compactation. After infiltration, this chelate can be transformed in situ by sol-gel method that leads to tetragonal phases in zirconia, which in turn, transforms to monoclinic structure on heating. Based on Differential Thermal Analysis (DTA), Fourier Transformed Infrared (FTIR), X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM), we confirm the reaction sequence to obtain the tetramer, the phase transformation sequence within the Al matrix, and the development of phases that leads to the synthesis of the Al-ZrO₂ composite.     

Improving deep learning performance with missing values via deletion and compensation

Neural Computing and Applications - Missing values in a dataset is one of the most common difficulties in real applications. Many different techniques based on machine learning have been proposed...     

Performance analysis of No-Propagation and ELM algorithms in classification

Neural Computing and Applications - The growing volume and complexity of data has led to the development of the so-called linear algorithms for neural networks like ELM, which maintain the...     

Effects of dopaminergic drugs on innate pheromone-mediated reward in female mice: A new case of dopamine-independent "liking."

Male sexual pheromones are innately rewarding to adult female mice, but the role of dopamine in this natural reward is unknown. The authors have tackled this issue by assessing the effects of intraperitoneal injections of dopamine D? (SCH 23390, 0.02- 0.05mg/kg) and D? (sulpiride, 20.00 mg/kg) antagonists, a dopamine releasing agent (amphetamine, 0.50 -2.00 mg/kg), and D? (SKF 38393, 10.00 -20.00 mg/kg) and D? (quinpirole, 0.20 -1.00 mg/kg) agonists on the chemoinvestigation displayed by female mice in male- versus female-soiled bedding 2-choice tests. Dopamine antagonists and quinpirole failed to affect the unconditioned preference displayed by females towards male chemosignals, whereas both amphetamine and SKF 38393 abolished it. Finally, D? and D? antagonists did not block the induction of operant place conditioning by male chemosignals. As the female mice were tested in their first encounter with male sexual pheromones, their behavior can only be influenced by the "liking" component of reward. Therefore, the results suggest that dopamine mediates neither the hedonic properties of male sexual pheromones nor the acquisition of conditioned place preference. However, dopamine acting on D1 receptors might inhibit female mice attraction towards male chemosignals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heavy metals in human bones in different historical epochs

The concentration of the metals lead, copper, zinc, cadmium and iron was determined in bone remains belonging to 30 individuals buried in the Region of Cartagena dating from different historical periods and in eight persons who had died in recent times. The metals content with respect to lead, cadmium and copper was determined either by anodic stripping voltammetry or by atomic absorption spectroscopy on the basis of the concentrations present in the bone remains. In all cases, zinc and iron were quantified by means of atomic absorption spectroscopy. The lead concentrations found in the bone remains in our city are greater than those reported in the literature for other locations. This led to the consideration of the sources of these metals in our area, both the contribution from atmospheric aerosols as well as that from the soil in the area. Correlation analysis leads us to consider the presence of the studied metals in the analysed bone samples to be the consequence of analogous inputs, namely the inhalation of atmospheric aerosols and diverse contributions in the diet. The lowest values found in the studied bone remains correspond to the Neolithic period, with similar contents to present-day samples with respect to lead, copper, cadmium and iron. As regards the evolution over time of the concentrations of the metals under study, a clear increase in these is observed between the Neolithic period and the grouping made up of the Bronze Age, Roman domination and the Byzantine period. The trend lines used to classify the samples into 7 periods show that the maximum values of lead correspond to the Roman and Byzantine periods. For copper, this peak is found in the Byzantine Period and for iron, in the Islamic Period. Zinc shows an increasing tendency over the periods under study and cadmium is the only metal whose trend lines shows a decreasing slope.     

Late onset epileptic crisis and cerebrovascular disease

INTRODUCTION: Stroke is the most frequent cause of epilepsy in adults, specially in those over 60 years old. Our aim was to analyze the etiologic relevance of stroke among the different etiologies of late onset seizures and to evaluate the clinical characteristics of the subgroup of patients with late onset seizures associated to stroke. PATIENTS AND METHODS: Patients aged over 20 who were admitted to the Neurology or Neurosurgery departments in our hospital for a first-ever seizure over a period of five years were identified retrospectively. The total number of patients included was 248. RESULTS: The most frequent etiologies were stroke (26.2%), tumors (26.2%), unknown (24.6%) and chronic alcohol intake (18.5%). Stroke was the most frequent etiology in patients over 60 (50%). Five of the 65 patients with stroke related seizures had suffered an intracranial hemorrhage and the rest had ischemic lesions. Seven patients had clinically silent infarctions. Seizures were generalized in 60% of the cases. Nearly in all the patients lesions were placed close to the cortex and mainly in carotid artery territory. CONCLUSIONS: Late onset seizures are due to a lesion in the brain in an important number of cases. Stroke is the most prevalent cause and this prevalence increases with age. A complete diagnostic procedures is warranted in this patients.     

Synthesis of fluorescent dendrimers with an oligo(phenylenevinylene) core

Novel fluorescent dendrimers of first, second, and third generation bearing a conjugated oligo(phenylenevinylene) (OPV) core and peripherial allyl chains as dendrons have been synthesized by a convergent method. The compounds have been fully characterized by 1H, 13C NMR, FTIR, UV-vis, and fluorescence spectroscopy, MALDI-TOF or FAB+ mass spectroscopy and elemental analysis. All dendrimers showed in solution a blue fluorescence with a maximum wavelength at 444-446 nm and can be deposited as thin films emitting in the blue-green region. The most homogeneous films were obtained for the second generation dendrimer which also exhibits the higher quantum yield in solution. These properties make it a possible candidate for application in organic light emitting diodes (OLEDs).