Identification of the yeast ARG-11 gene as a mitochondrial ornithine carrier involved in arginine biosynthesis

The ARG-11 gene in Saccharomyces cerevisiae encodes a protein with the characteristic features of a family of 35 related membrane proteins that are encoded in the fungal genome. Some of them are known to transport various substrates and products across the inner membranes of mitochondria, but the functions of 29 members of the family are unknown. The yeast ARG-11 protein has been over-produced as inclusion bodies in Escherichia coli. It has been solubilized in the presence of sarkosyl, re-constituted into liposomes and shown to transport ornithine in exchange for protons. Its main physiological role is probably to take ornithine synthesized from glutamate in the mitochondrial matrix to the cytosol where it is converted to arginine.     

Experimental investigation on fire endurance of insulated concrete beams strengthened with near surface mounted FRP bar reinforcement

Fiber reinforced polymer (FRP) composites are known to be susceptible to deterioration at elevated temperature. To evaluate the feasibility of achieving a fire-rated FRP system an investigation was undertaken to examine and document the performance of near surface mounted (NSM) FRP strengthened concrete beams under fire conditions. Twelve reinforced concrete beams were strengthened in flexure with NSM FRP bars and insulated with different insulation systems. The specimens were subsequently exposed to a standard fire while subjected to full service load. Tests results on fire indicated that insulated NSM FRP strengthened beams can achieve a fire endurance of at least 2 h. Moreover structural testing to failure at room temperature of the fire testes beams has shown that well insulated members are able to retain (part of) their original strengthened flexural capacity.     

CACNA1A Mutations Causing Early Onset Ataxia: Profiling Clinical,Dysmorphic and Structural-Functional Findings

The CACNA1A gene encodes the pore-forming α_1A subunit of the voltage-gated Ca_V2.1 Ca²⁺ channel, essential in neurotransmission, especially in Purkinje cells. Mutations in CACNA1A result in great clinical heterogeneity with progressive symptoms, paroxysmal events or both. During infancy, clinical and neuroimaging findings may be unspecific, and no dysmorphic features have been reported. We present the clinical, radiological and evolutionary features of three patients with congenital ataxia, one of them carrying a new variant. We report the structural localization of variants and their expected functional consequences. There was an improvement in cerebellar syndrome over time despite a cerebellar atrophy progression, inconsistent response to acetazolamide and positive response to methylphenidate. The patients shared distinctive facial gestalt: oval face, prominent forehead, hypertelorism, downslanting palpebral fissures and narrow nasal bridge. The two α_1A affected residues are fully conserved throughout evolution and among the whole human Ca_V channel family. They contribute to the channel pore and the voltage sensor segment. According to structural data analysis and available functional characterization, they are expected to exert gain- (F1394L) and loss-of-function (R1664Q/R1669Q) effect, respectively. Among the CACNA1A-related phenotypes, our results suggest that non-progressive congenital ataxia is associated with developmental delay and dysmorphic features, constituting a recognizable syndromic neurodevelopmental disorder.     

A nonlinear,recurrence-based approach to traffic classification

The ability to accurately classify and identify the network traffic associated with different applications is a central issue for many network operation and research topics including Quality of Service enforcement, traffic engineering, security, monitoring and intrusion-detection. However, traditional classification approaches for traffic to higher-level application mapping, such as those based on port or payload analysis, are highly inaccurate for many emerging applications and hence useless in actual networks. This paper presents a recurrence plot-based traffic classification approach based on the analysis of non-stationary “hidden” transition patterns of IP traffic flows. Such nonlinear properties cannot be affected by payload encryption or dynamic port change and hence cannot be easily masqueraded. In performing a quantitative assessment of the above transition patterns, we used recurrence quantification analysis, a nonlinear technique widely used in many fields of science to discover the time correlations and the hidden dynamics of statistical time series. Our model proved to be effective for providing a deterministic interpretation of recurrence patterns derived by complex protocol dynamics in end-to-end traffic flows, and hence for developing qualitative and quantitative observations that can be reliably used in traffic classification.     

Theoretical analysis of evolutionary algorithms with an infinitepopulation size in continuous space. Part I: Basic properties ofselection and mutation

This paper aims at establishing fundamental theoretical properties for a class of "genetic algorithms" in continuous space (GACS). The algorithms employ operators such as selection, crossover, and mutation in the framework of a multidimensional Euclidean space. The paper is divided into two parts. The first part concentrates on the basic properties associated with the selection and mutation operators. Recursive formulae for the GACS in the general infinite population case are derived and their validity is rigorously proven. A convergence analysis is presented for the classical case of a quadratic cost function. It is shown how the increment of the population mean is driven by its own diversity and follows a modified Newton's search. Sufficient conditions for monotonic increase of the population mean fitness are derived for a more general class of fitness functions satisfying a Lipschitz condition. The diversification role of the crossover operator is analyzed in Part II. The treatment adds much light to the understanding of the underlying mechanism of evolution-like algorithms.     

Reflectometric measurements of polarization properties in optical-fiber links

Polarization sensitive reflectometric measurements are effective tools for the characterization of polarization properties of optical-fiber links. These techniques show two advantages compared with the standard ones: they can perform measurements using only one fiber end (both for transmission and for reception of the probe signal) and, most important, they can characterize the local evolution of the polarization properties of the fiber link. Reflectometric measurements of differential group delay and fiber birefringence have been already successfully performed. More recently, the possibility of measuring, also, polarization dependent loss has been theoretically explored. In this paper the theory and main applications of polarization sensitive reflectometric techniques are reviewed.     

An analytical formula for the mean differential group delay of randomly birefringent spun fibers

Polarization-mode dispersion (PMD) is a serious impairment for high-bit-rate optical telecommunication systems. It is known that spinning the fiber during the drawing process drastically reduces the PMD. However, the analysis of pulse propagation through a randomly birefringent spun fiber is still at an early stage. In this paper, we derive an analytical formula for the mean differential group delay of a periodically spun fiber with random birefringence. We model the birefringence with fixed modulus and a random orientation under the condition that the spin period is shorter than the beat length. Finally, we numerically compare the analytical results with those given by the random-modulus model of birefringence, and we obtain good agreement as long as the short-period assumption is satisfied.     

A prospective study of simplified omeprazole suspension for the prophylaxis of stress-related mucosal damage

OBJECTIVES: To determine the efficacy, safety, and cost of simplified omeprazole suspension in mechanically ventilated critically ill patients who have at least one additional risk factor for stress-related mucosal damage. DESIGN: Prospective, open-label study. SETTING: Surgical intensive care and burn unit at a university tertiary care center. PATIENTS: Seventy-five adult, mechanically ventilated patients with at least one additional risk factor for stress-related mucosal damage. INTERVENTIONS: Patients received 20 mL of simplified omeprazole suspension (containing 40 mg of omeprazole) initially, followed by a second 20-mL dose 6 to 8 hrs later, then 10 mL (20 mg) daily. Simplified omeprazole suspension was administered through a nasogastric tube, followed by 5 to 10 mL of tap water. The nasogastric tube was clamped for 1 to 2 hrs after each administration. MEASUREMENTS AND MAIN RESULTS: The primary outcome measure was clinically significant gastrointestinal bleeding determined by endoscopic evaluation, nasogastric aspirate examination, or heme-positive coffee ground material that did not clear with lavage, which was associated with at least a 5% decrease in hematocrit. Secondary efficacy measures were gastric pH measured 4 hrs after omeprazole was first administered, mean gastric pH after omeprazole was started, and the lowest gastric pH during omeprazole therapy. Safety-related outcomes included the occurrence rate of adverse events and pneumonia. No patient experienced clinically significant upper gastrointestinal bleeding after receiving omeprazole suspension. The 4-hr postomeprazole mean gastric pH was 7.1, the mean gastric pH after starting omeprazole was 6.8, and the mean lowest pH after starting omeprazole was 5.6. The occurrence rate of pneumonia was 12%. No patient in this high-risk population experienced an adverse event or a drug interaction that was attributable to omeprazole. CONCLUSIONS: Simplified omeprazole suspension prevented clinically significant upper gastrointestinal bleeding and maintained gastric pH of > 5.5 in mechanically ventilated critical care patients without producing toxicity.