Characterization of Linear Low-Density Polyethylene/ Poly(vinyl alcohol) Blends and Their Biodegradability by Vibrio sp. Isolated from Marine Benthic Environment

Increasing amounts of plastic waste in the environment have become a problem of gigantic proportions. The case of linear low-density polyethylene (LLDPE) is especially significant as it is widely used for packaging and other applications. This synthetic polymer is normally not biodegradable until it is degraded into low molecular mass fragments that can be assimilated by microorganisms. Blends of nonbiodegradable polymers and biodegradable commercial polymers such as poly (vinyl alcohol) (PVA) can facilitate a reduction in the volume of plastic waste when they undergo partial degradation. Further, the remaining fragments stand a greater chance of undergoing biodegradation in a much shorter span of time. In this investigation, LLDPE was blended with different proportions of PVA (5–30%) in a torque rheometer. Mechanical, thermal, and biodegradation studies were carried out on the blends. The biodegradability of LLDPE/PVA blends has been studied in two environments: (1) in a culture medium containing Vibrio sp. and (2) soil environment, both over a period of 15 weeks. Blends exposed to culture medium degraded more than that exposed to soil environment. Changes in various properties of LLDPE/PVA blends before and after degradation were monitored using Fourier transform infrared spectroscopy, a differential scanning calorimeter (DSC) for crystallinity, and scanning electron microscope (SEM) for surface morphology among other things. Percentage crystallinity decreased as the PVA content increased and biodegradation resulted in an increase of crystallinity in LLDPE/PVA blends. The results prove that partial biodegradation of the blends has occurred holding promise for an eventual biodegradable product

Queues with inter- ruption in Random/ Markovian Environment

In many situations probability models are more realistic than deterministic models. Several phenomena occurring in physics are studied as random phenomena changing with time and space. Stochastic processes originated from the needs of physicists.Let X(t) be a random variable where t is a parameter assuming values from the set T. Then the collection of random variables {X(t), t ∈ T} is called a stochastic process. We denote the state of the process at time t by X(t) and the collection of all possible values X(t) can assume, is called state space

El FONVIS: su trayectoria institucional en el contexto sociopolitíco venezolana de 1980 a 2004

In Venezuela wurden ab 1989 als Reaktion auf die Zahlungsunfähigkeit des Landes erste neoliberale Strukturanpassungsmaßnahmen eingeleitet. Eine daraus resultierende zusätzliche Belastung der armen Bevölkerung mündete in einen völlig unerwarteten, massiven sozialen Aufruhr, dem sogenannten caracazo von 1989. Als eine Antwort darauf gründete die Regierung in Kooperation mit der Interamerikanischen Entwicklungsbank (BID) den venezolanischen Sozialfond FONVIS, der die sozialen Auswirkungen der neoliberalen Anpassung abfedern sollte. In diesem working paper werden unter Berücksichtigung der nationalen Kontextbedingungen die historische Entwicklung und die verschiedenen Konfigurationen des FONVIS beschrieben und analysiert. Als international gefördertes Implementierungsinstrument startete der Fonds mit einer Armutsbekämpfungspolitik, die den Ausbau von sozialer Infrastruktur sowie die Unterstützung des venezolanischen Dezentralisierungsprozesses fokussierte. Mit dem Regierungsantritt von Hugo Chávez 1999 hatte der Fonds dann in einem zunehmend schwierigeren Kontext zu operieren: Durch den Aufbau von neuen zentralstaatlichen sozialpolitischen Instrumenten und regierungsnahen ad hoc-Instanzen wurde der FONVIS zunehmend von einer anfänglich wichtigen Stellung innerhalb der nationalen Sozialpolitik ins institutionelle Abseits verdrängt und schließlich Ende 2005 offiziell aufgelöst. Die hier analysierte Performance des FONVIS macht deutlich, dass in der venezolanischen Fondslandschaft sich nur schwer eine breit entfaltete Multi-Level-Governance entwickeln konnte, weil der nationalstaatliche Kontext die Fondspolitik in allen Momenten dominierte. Schließlich leitete der Staat sogar ohne weitere Absprachen weder mit der internationalen noch regionalen und lokalen Ebene die Abschaffung des Fonds ein.

Influence of the buffer environment on the Relative Biological Effectiveness of carbon ion radiation, investigated by Scanning Force Microscopy and gel electrophoresis

This work focuses on the analysis of the influence of environment on the relative biological effectiveness (RBE) of carbon ions on molecular level. Due to the high relevance of RBE for medical applications, such as tumor therapy, and radiation protection in space, DNA damages have been investigated in order to understand the biological efficiency of heavy ion radiation. The contribution of this study to the radiobiology research consists in the analysis of plasmid DNA damages induced by carbon ion radiation in biochemical buffer environments, as well as in the calculation of the RBE of carbon ions on DNA level by mean of scanning force microscopy (SFM). In order to study the DNA damages, besides the common electrophoresis method, a new approach has been developed by using SFM. The latter method allows direct visualisation and measurement of individual DNA fragments with an accuracy of several nanometres. In addition, comparison of the results obtained by SFM and agarose gel electrophoresis methods has been performed in the present study. Sparsely ionising radiation, such as X-rays, and densely ionising radiation, such as carbon ions, have been used to irradiate plasmid DNA in trishydroxymethylaminomethane (Tris buffer) and 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES buffer) environments. These buffer environments exhibit different scavenging capacities for hydroxyl radical (HO0), which is produced by ionisation of water and plays the major role in the indirect DNA damage processes. Fragment distributions have been measured by SFM over a large length range, and as expected, a significantly higher degree of DNA damages was observed for increasing dose. Also a higher amount of double-strand breaks (DSBs) was observed after irradiation with carbon ions compared to X-ray irradiation. The results obtained from SFM measurements show that both types of radiation induce multiple fragmentation of the plasmid DNA in the dose range from D = 250 Gy to D = 1500 Gy. Using Tris environments at two different concentrations, a decrease of the relative biological effectiveness with the rise of Tris concentration was observed. This demonstrates the radioprotective behavior of the Tris buffer solution. In contrast, a lower scavenging capacity for all other free radicals and ions, produced by the ionisation of water, was registered in the case of HEPES buffer compared to Tris solution. This is reflected in the higher RBE values deduced from SFM and gel electrophoresis measurements after irradiation of the plasmid DNA in 20 mM HEPES environment compared to 92 mM Tris solution. These results show that HEPES and Tris environments play a major role on preventing the indirect DNA damages induced by ionising radiation and on the relative biological effectiveness of heavy ion radiation. In general, the RBE calculated from the SFM measurements presents higher values compared to gel electrophoresis data, for plasmids irradiated in all environments. Using a large set of data, obtained from the SFM measurements, it was possible to calculate the survive rate over a larger range, from 88% to 98%, while for gel electrophoresis measurements the survive rates have been calculated only for values between 96% and 99%. While the gel electrophoresis measurements provide information only about the percentage of plasmids DNA that suffered a single DSB, SFM can count the small plasmid fragments produced by multiple DSBs induced in a single plasmid. Consequently, SFM generates more detailed information regarding the amount of the induced DSBs compared to gel electrophoresis, and therefore, RBE can be calculated with more accuracy. Thus, SFM has been proven to be a more precise method to characterize on molecular level the DNA damage induced by ionizing radiations.

Ecosystem services and adaptation for agriculture and food security: analysis of two decades (1991–2011) of financing by the Global Environment Facility

Investing in global environmental and adaptation benefits in the context of agriculture and food security initiatives can play an important role in promoting sustainable intensification. This is a priority for the Global Environment Facility (GEF), created in 1992 with a mandate to serve as financial mechanism of several multilateral environmental agreements. To demonstrate the nature and extent of GEF financing, we conducted an assessment of the entire portfolio over a period of two decades (1991–2011) to identify projects with direct links to agriculture and food security. A cohort of 192 projects and programs were identified and used as a basis for analyzing trends in GEF financing. The projects and programs together accounted for a total GEF financing of US$1,086.8 million, and attracted an additional US$6,343.5 million from other sources. The value-added of GEF financing for ecosystem services and resilience in production systems was demonstrated through a diversity of interventions in the projects and programs that utilized US$810.6 million of the total financing. The interventions fall into the following four main categories in accordance with priorities of the GEF: sustainable land management (US$179.3 million), management of agrobiodiversity (US$113.4 million), sustainable fisheries and water resource management (US$379.8 million), and climate change adaptation (US$138.1 million). By aligning GEF priorities with global aspirations for sustainable intensification of production systems, the study shows that it is possible to help developing countries tackle food insecurity while generating global environmental benefits for a healthy and resilient planet.

La participaci??n institucional y la participaci??n en la gesti??n y el control de los centros educativos

Monogr??fico con el t??tulo: 'Los consejos escolares, cauces de participaci??n de la comunidad educativa'. Resumen basado en el de la publicaci??n

II Encuentro Institucional del Consejo Escolar de la Regi??n de Murcia, Consejos Escolares Municipales y Consejos Escolares de Centro : la participaci??n como factor de mejora de la calidad educativa

Esta publicaci??n recoge los estudios, ponencias y conclusiones de un trabajo realizado a lo largo de todo un curso escolar y que ha cristalizado en el II Encuentro de consejos escolares (regional, municipales y de centros) en el que se llev?? a cabo un debate sobre la participaci??n en los centros en los centros que abord?? los siguientes temas: la participaci??n en la UE, programa para la mejora de la participaci??n en la Comunidad Valenciana y en la de Madrid y an??lisis de la participaci??n en Consejos Escolares en las Comarcas del Noroeste y R??o Mula de la Regi??n de Murcia.

III Encuentro Institucional del Consejo Escolar de la Regi??n de Murcia, Consejos Escolares Municipales y Consejos Escolares de Centro

El libro presenta las actas del tercer encuentro regional de consejos escolares dedicado al tema de la formaci??n del profesorado y al papel del profesor en el siglo XXI, su formaci??n inicial y permanente, sus relaciones con la sociedad y la tutor??a como factor clave en la mejora de la calidad de la ense??anza. A la ponencia sobre formaci??n del profesorado en Europa siguieron los informes de los presidentes de las comisiones de trabajo preparatorias del encuentro.

IV encuentro institucional del Consejo Escolar de la Regi??n de Murcia, Consejos Escolares Municipales y de Centro : la formaci??n de padres, un modelo de actuaci??n para la Regi??n de Murcia

El cuarto encuentro institucional del Consejo Escolar de la Regi??n de Murcia con los consejos municipales y de centro se dedic?? a la formaci??n de padres como protagonistas del proceso educativo de sus hijos. El libro recoge las intervenciones de los ponentes y un resumen de las 37 comunicaciones recibidas.

VI Encuentro institucional con los consejos escolares municipales y de centros : las evaluaciones del sistema educativo : evaluamos para progresar

Encuentro regional de consejos escolares en el que se trat?? el tema de las evaluaciones del sistema educativo, present??ndose siete ponencias sobre: el programa PISA de la OCDE, evaluaci??n de programas, evaluci??n de procesos de ense??anza-aprendizaje, evaluaci??n de centros, de sistemas educativos y la participaci??n de los padres en la educaci??n.

VI Encuentro Institucional del Consejo Escolar de la Regi??n de Murcia con Consejos Escolares Municipales y de Centro : las evaluaciones del sistema educativo : evaluamos para progresar. Conclusiones

En este CD se encuentran las ponencias del libro que, con el mismo t??tulo, se public?? en el a??o 2006.- Incluye im??genes del Encuentro.

A Distributed Model for Mobile Robot Environment-Learning and Navigation

A distributed method for mobile robot navigation, spatial learning, and path planning is presented. It is implemented on a sonar-based physical robot, Toto, consisting of three competence layers: 1) Low-level navigation: a collection of reflex-like rules resulting in emergent boundary-tracing. 2) Landmark detection: dynamically extracts landmarks from the robot's motion. 3) Map learning: constructs a distributed map of landmarks. The parallel implementation allows for localization in constant time. Spreading of activation computes both topological and physical shortest paths in linear time. The main issues addressed are: distributed, procedural, and qualitative representation and computation, emergent behaviors, dynamic landmarks, minimized communication.

Enhanced Reality Visualization in a Surgical Environment

Enhanced reality visualization is the process of enhancing an image by adding to it information which is not present in the original image. A wide variety of information can be added to an image ranging from hidden lines or surfaces to textual or iconic data about a particular part of the image. Enhanced reality visualization is particularly well suited to neurosurgery. By rendering brain structures which are not visible, at the correct location in an image of a patient's head, the surgeon is essentially provided with X-ray vision. He can visualize the spatial relationship between brain structures before he performs a craniotomy and during the surgery he can see what's under the next layer before he cuts through. Given a video image of the patient and a three dimensional model of the patient's brain the problem enhanced reality visualization faces is to render the model from the correct viewpoint and overlay it on the original image. The relationship between the coordinate frames of the patient, the patient's internal anatomy scans and the image plane of the camera observing the patient must be established. This problem is closely related to the camera calibration problem. This report presents a new approach to finding this relationship and develops a system for performing enhanced reality visualization in a surgical environment. Immediately prior to surgery a few circular fiducials are placed near the surgical site. An initial registration of video and internal data is performed using a laser scanner. Following this, our method is fully automatic, runs in nearly real-time, is accurate to within a pixel, allows both patient and camera motion, automatically corrects for changes to the internal camera parameters (focal length, focus, aperture, etc.) and requires only a single image.

Segmentation and Alignment of Speech and Sketching in a Design Environment

Sketches are commonly used in the early stages of design. Our previous system allows users to sketch mechanical systems that the computer interprets. However, some parts of the mechanical system might be too hard or too complicated to express in the sketch. Adding speech recognition to create a multimodal system would move us toward our goal of creating a more natural user interface. This thesis examines the relationship between the verbal and sketch input, particularly how to segment and align the two inputs. Toward this end, subjects were recorded while they sketched and talked. These recordings were transcribed, and a set of rules to perform segmentation and alignment was created. These rules represent the knowledge that the computer needs to perform segmentation and alignment. The rules successfully interpreted the 24 data sets that they were given.

Component based recognition of objects in an office environment

We present a component-based approach for recognizing objects under large pose changes. From a set of training images of a given object we extract a large number of components which are clustered based on the similarity of their image features and their locations within the object image. The cluster centers build an initial set of component templates from which we select a subset for the final recognizer. In experiments we evaluate different sizes and types of components and three standard techniques for component selection. The component classifiers are finally compared to global classifiers on a database of four objects.