Mathematical modelling of the alcoholic fermentation of glucose by Zymomonas mobilis mobilis

The kinetics of alcoholic fermentation of a strain of Zymomonas mobilis, isolated from sugarcane juice, has been studied with the objective of determining the constansts of a non-structured mathematical model that represents the fermentation process. Assays in batch and in continuous culture have been carried out with different initial concentrations of glucose. The final concentrations of glucose, ethanol and biomass were determined. The following kinetic parameters were obtained: μ_max, 0·5 h^?1; K_s, 4·64 g dm^?3; P_max, 106 g dm^?3; Y_x/s, 0·0265 g g^?1; m, 1·4 g g^?1 h^?1; α, 17·38 g g^?1; β, 0·69 g g^?1 h^?1.     

Neuropsychological impairment in female alcoholics: Replication and extension.

In 2 separate studies, female alcoholics (N?=?50) performed significantly poorer on 12 neuropsychological tests (e.g., the WAIS and the Bender-Gestalt Test) than female nonalcoholic controls (N?=?50). The pattern of deficit was consistent across studies and similar to that reported for male alcoholics: intact verbal skills but impaired nonverbal abstracting, visual-spatial, and problem-solving abilities. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Erosional and depositional features produced by a convulsive event,San Carlos,Colombia, September 21, 1990

The upper catchment, of the San Carlos River, located on the eastern slope of the Colombian Central Cordillera, was affected by a rainstorm which had no historic equivalent in the area, caused 20 deaths and important destruction and therefore might be called convulsive in the sense of Clifton (1988). Steep upper slopes suffered more than one hundred shallow mudflows. In the catchment channel deepening and widening cut through older torrential and slope deposits and weathered granodiorite, A large amount of material was eroded including blocks up to 8 m in diameter. Resultings deposits show the well-known differentiation: blocks accumulated in the upper part, coarse and settled in the intermediate course and clay was carried to the Punchinà Reservois about 20 km downstream. A volcanic ash layer which covers the older torrential deposits shows mineral assemblages which may enable its correlation with other ashes found eastward with an age estimated in about 10.500 years BP.     

Fast multiscale modeling of cardiac electrophysiology including Purkinje system

In this paper, we present a modeling methodology to couple the cardiac conduction system to cardiac myocytes through a model of Purkinje-ventricular junctions to yield fast and realistic electrical activation of the ventricles. A patient-specific biventricular geometry is obtained from processing computed tomography scan data. A one-manifold implementation of the fast marching method based on Eikonal-type equations is used for modeling heart electrophysiology, which facilitates the multiscale 1-D-3-D coupling at very low computational costs. The method is illustrated in in-silico experiments where we analyze and compare alternative pacing strategies on the same patient-specific anatomy. We also show very good agreement between the results from the proposed approach and more detailed and comprehensive biophysical models for modeling cardiac electrophysiology. The effect of atrioventricular delay on the distribution of activation time in myocardium is studied with two experiments. Given the reasonable computational times and realistic activation sequences provided by our method, it can have an important clinical impact on the selection of optimal implantation sites of pacing leads or placement of ablation catheter's tip in the context of cardiac rhythm management therapies.     

Characterization of the chemically deposited hydroxyapatite coating on a titanium substrate

Bioactive hydroxyapatite (HA) coating on titanium (Ti) implant can be used as a drug delivery device. A controlled release of drug around the implant requires the incorporation of drug into the coating material during the coating process. HA coating was prepared using a two-step procedure in conditions suitable for simultaneous incorporation of the protein-based drug into the coating material. Monetite coating was deposited on Ti substrate in acidic condition followed by the transformation of the monetite coating to HA. X-ray diffraction (XRD) confirmed the formation of the monetite phase at the first step of the coating preparation, which was transformed into HA at the second step. Fourier transform infrared spectroscopy demonstrated typical bands of a crystallized carbonated HA with A- and B-type substitution, which was confirmed by the XRD refinement of the structural parameters. Scanning electron microscope was used to observe the morphology of monetite and HA coatings. Adhesion of the coatings was measured using a scratch tester. The critical shearing stress was found to be 84.20 ± 1.27 MPa for the monetite coating, and 44.40 ± 2.39 MPa for the HA coating.     

Using OGRO and CertiVeR to improve OCSP validation for Grids

Authentication and authorization in many distributed systems rely on the use of cryptographic credentials that in most of the cases have a defined lifetime. This feature mandates the use of mechanisms able to determine whether a particular credential can be trusted at a given moment. This process is commonly named validation. Among available validation mechanisms, the Online Certificate Status Protocol (OCSP) stands out due to its ability to carry near real time certificate status information. Despite its importance for security, OCSP faces considerable challenges in the computational Grid (i.e. Proxy Certificate’s validation) that are being studied at the Global Grid Forum’s CA Operations Work Group (CAOPS-WG). As members of this group, we have implemented an OCSP validation infrastructure for the Globus Toolkit 4, composed of the CertiVeR Validation Service and our Open GRid Ocsp (OGRO) client library, which introduced the Grid Validation Policy. This paper summarizes our experiences on that work and the results obtained up to now. Furthermore we introduce the prevalidation concept, a mechanism analogous to the Authorization Push-Model, capable of improving OCSP validation performance in Grids. This paper also reports the results obtained with OGRO’s prevalidation rules for Grid Services as a proof of concept.

Antialiasing filter design for subpixel downsampling via frequency-domain analysis

In this paper, we are concerned with image downsampling using subpixel techniques to achieve superior sharpness for small liquid crystal displays (LCDs). Such a problem exists when a high-resolution image or video is to be displayed on low-resolution display terminals. Limited by the low-resolution display, we have to shrink the image. Signal-processing theory tells us that optimal decimation requires low-pass filtering with a suitable cutoff frequency, followed by downsampling. In doing so, we need to remove many useful image details causing blurring. Subpixel-based downsampling, taking advantage of the fact that each pixel on a color LCD is actually composed of individual red, green, and blue subpixel stripes, can provide apparent higher resolution. In this paper, we use frequency-domain analysis to explain what happens in subpixel-based downsampling and why it is possible to achieve a higher apparent resolution. According to our frequency-domain analysis and observation, the cutoff frequency of the low-pass filter for subpixel-based decimation can be effectively extended beyond the Nyquist frequency using a novel antialiasing filter. Applying the proposed filters to two existing subpixel downsampling schemes called direct subpixel-based downsampling (DSD) and diagonal DSD (DDSD), we obtain two improved schemes, i.e., DSD based on frequency-domain analysis (DSD-FA) and DDSD based on frequency-domain analysis (DDSD-FA). Experimental results verify that the proposed DSD-FA and DDSD-FA can provide superior results, compared with existing subpixel or pixel-based downsampling methods.     

Leveraging agriculture to improve nutrition in the Philippines

The typical Filipino diet mainly consists of rice, fish and vegetables, with rice being the greatest source of calories. The consumption of a maize, starchy roots and tubers as rice substitutes or supplements, and vegetables and fruits has generally declined, while the consumption of fats, oils and meats has increased. Stunting is the most prevalent form of malnutrition among Filipinos. Vitamin A Deficiency, Iodine Deficiency Disorder, and Iron Deficiency Anemia remain public health problems for children and pregnant and lactating women. The link between nutrition and agriculture in the Philippines has focused on leveraging agriculture to improve nutrition. The programs that had been initiated by the government, NGO/CSO or private sector were conceptualized and implemented before the elements of a nutrition-sensitive agriculture framework were identified. These programs were implemented to address food production and the nutritional needs of individuals, families, and communities only with reference to nutrition security. Many of these programs have been successful as they implemented best practices that could be applied to forge a superior approach that optimizes the agriculture-nutrition nexus. This study identified these best practices or elements of success. The elements that have been noted as reasons for the success of some of these programs are: presence of strong political will and enabling policy environment; forging of new forms of partnerships, strategic collaboration, sound coordination and structures; exploiting the best that science and technology could offer; democratizing community participation; strong capacity building component and access to reliable technical expertise; knowledge and sensitivity to local cultures, beliefs and practices; professionalized promotion and ‘messaging’; use of catchy terms for easy recall; availability of sustainable funding; use of the life cycle approach in nutrition; holistic community nutrition perspective; practice and promotion of biodiversity-based agricultural production system; and control of the means of production.