Integrins alpha v beta 3 and alpha v beta 5 contribute to cell attachment to vitronectin but differentially distribute on the cell surface.

We investigated the role of the integrins alpha v beta 3 and alpha v beta 5 in mediating vitronectin adhesion of three phenotypically distinct cell types. M21 human melanoma cells and H2981 lung carcinoma cells use both alpha v-containing integrins in adhering to vitronectin while UCLA-P3 lung carcinoma cells adhere exclusively with alpha v beta 5. Specifically, monoclonal antibodies directed to functional epitopes on both receptors were required to block adhesion of M21 or H2981 cells while adhesion of UCLA-P3 cells to vitronectin could be blocked with a monoclonal antibody to alpha v beta 5. Although both receptors are involved in M21 and H2981 cell adhesion to vitronectin, only alpha v beta 3 can be detected in focal contacts, colocalizing with vinculin, talin, and the ends of actin filaments, while alpha v beta 5 shows a distinct, nonfocal contact, distribution on the cell surface. These results provide the first evidence that two homologous integrins that recognize the same ligand distribute differentially on the cell surface

JPEG steganography with particle swarm optimization accelerated by AVX

Digital steganography aims at hiding secret messages in digital data transmitted over insecure channels. The JPEG format is prevalent in digital communication, and images are often used as cover objects in digital steganography. Optimization methods can improve the properties of images with embedded secret but introduce additional computational complexity to their processing. AVX instructions available in modern CPUs are, in this work, used to accelerate data parallel operations that are part of image steganography with advanced optimizations.Web of Science328art. no. e544

Desarrollo de una nueva metodología de transformación genética no tradicional, como estrategia potencial para incluir resistencia a infecciones fúngicas en vainilla (Vainilla Planifolia).

Proyecto de Investigación (Código: 5402-2160-2701) Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE). Escuela de Ciencias y Letras, 2012Este estudio consistió en la evaluación de las condiciones experimentales para laransformación genética de Vanilla planifolia por medio de un sistema de biobalística de baja presión. Los meristemos radicales de aproximadamente 0.5 cm, provenientes de microestacas desarrolladas en un medio líquido MS básico en agitación, se colocaron en un medio osmótico 16 hr antes y 24 hr después del bombardeo, posteriormente se subcultivaron en medio MS suplementado con 1 y 3 mg/L de benciladenina. Se incluyeron controles de bombardeo sin plásmido y controles de explantes, con y sin estrés osmótico. 48 hr después del bombardeo se realizó la prueba de expresión transitoria con el X-Gluc y se observó una tinción azulada en la epidermis de las terminales radicales bombardeadas con el plásmido así como también en los controles. A las 2 semanas también se presentó tinción en las regiones externa e interna de las estructuras iniciales que conducen a la formación de los PLBs en todos los tratamientos evaluados y los controles. La presencia de la tinción azul correspondiente a la degradación del sustrato X-Gluc en los controles, evidencia la expresión de enzimas endógenas en los tejidos de la planta que podrían interferir con la interpretación de los resultados de expresión transitoria. Este sería el primer reporte de actividad -glucoronidasa endógena en materiales in vitro de vainilla. De acuerdo a la evidencia obtenida, el estrés inducido por el choque osmótico en las terminales radicales de vainilla, puede provocar contaminación por un aumento en el crecimiento de potenciales microorganismos endógenos y por ende, la pérdida de material vegetal. Aunque es factible utilizar meristemos radicales de vainilla para la transformación genética de esta especie, se propone que una estructura más apropiada para este fin podría ser el estadio inicial observado cuando se forma el PLB a partir de los meristemos radicales. _______________________________________________________________________ Abstract: This study consisted in the evaluation of the experimental conditions for genetic transformation of Vanilla planifolia by a biolistic system under low pressure. Root tips of 0.5 cm of length, from seedlings developed in basic MS liquid medium under agitation, were placed in an osmotic medium, 16 hr before and 24 hr after bombarding, subsequently they were placed in MS culture medium supplemented with 1 and 3 mg/L benzyladenine. The assay included bombarding controls without plasmid and controls of explants with and without osmotic stress. After 48 hr of bombarding, root tips were exposed to X-Gluc and a blue staining was observed in the epidermis of the root tips, as well as in the controls. After 2 weeks, the blue staining was also present in the external and internal areas of the initial structures that become PLBs, in all the treatments evaluated and controls. The presence of the staining corresponding to X-Gluc substrate degradation in the controls evidences the expression of endogenous enzymes in plant tissue, which could interfere with interpretation of transient expression results. This would be the first report of endogenous -glucuronidase activity in in vitro vanilla materials. According to the obtained evidence, it is also important to take into consideration that stress induced by osmotic shock in the terminal tips of vanilla plants, could cause contamination by an increase in the growth of potential endogenous microorganisms and, consequently the loss of plant material. Although it is possible to utilize vanilla root meristems for genetic transformation of this species, it is postulated that a more appropriated structure for transformation could be the initial stage on the process of PLB formation from root meristems

Desarrollo de una metodología para el diagnóstico viral y la producción de plantas de camote libres de virus

Proyecto de Investigación (Código: 5402-2151-8701) Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE). Escuela de Ingeniería en Agronomía, 2013El objetivo general de este proyecto fue producir plantas de camote libre de virus. Para lograr este objetivo primero se identificaron los virus más comunes en los cantones de San Carlos y San Ramón (San Isidro de Peñas Blancas), utilizando la técnica NCM-ELISA, posteriormente se desarrolló un metodología para la limpieza viral, combinando la termoterapia con el cultivo de meristemos y se evaluó el crecimiento y la producción de esquejes provenientes de plantas libres de virus con esquejes provenientes de plantas de campo. Los resultados más importantes fueron, el principal virus detectado en la zona de estudio fue el SPFMV. El tratamiento de explantes a 40 ºC por 10 h y posterior extracción del meristemo produjo un 100% plantas libres de virus según el análisis NCM-Elisa. Por último, los esquejes procedentes de plantas in vitro libre de virus mostraron un mejor crecimiento y producción que aquellas provenientes de plantas de campo

Experiments and Modeling of Evaporating/Condensing Menisci

Discuss the Constrained Vapor Bubble (CVB) experiment and how it aims to achieve a better understanding of the physics of evaporation and condensation and how they affect cooling processes in microgravity using a remotely controlled microscope and a small cooling device

The Constrained Vapor Bubble Experiment - Interfacial Flow Region

Internal heat transfer coefficient of the CVB correlated to the presence of the interfacial flow region. Competition between capillary and Marangoni flow caused Flooding and not a Dry-out region. Interfacial flow region growth is arrested at higher power inputs. 1D heat model confirms the presence of interfacial flow region. 1D heat model confirms the arresting phenomena of interfacial flow region Visual observations are essential to understanding

Code wars: steganography, signals intelligence, and terrorism

This paper describes and discusses the process of secret communication known as steganography. The argument advanced here is that terrorists are unlikely to be employing digital steganography to facilitate secret intra-group communication as has been claimed. This is because terrorist use of digital steganography is both technically and operationally implausible. The position adopted in this paper is that terrorists are likely to employ low-tech steganography such as semagrams and null ciphers instead

Caracterización de Quassia amara para su manejo sostenible en ecosistemas naturales y agroforestales en Costa Rica

Proyecto de Investigación (Código: 5402 – 2151 – 6201) Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE). Escuela de Ingeniería en Agronomía, 2008El Hombre grande (Quassia amara) es una planta medicinal y tiene actividad biocida, la cual la hace ser de gran importancia en la producción de cultivos orgánicos. Sin embargo, existe una serie de limitaciones, como son la falta de una semilla apropiada para el establecimiento de las plantaciones. El objetivo principal de este proyecto fue caracterizar los genotipos de Quassia amara y su clonación. El estudio realizó una serie de evaluaciones para determinar la metodología para la micropropagación de esta planta, así como estudios preliminares de extracción de ADN para la caracterización molecular del hombre grande. Los resultados de estas investigaciones permitieron desarrollar una metodología para la extracción del ADN, pero no la caracterización molecular de los genotipos. Además, determinaron, que el explante recomendado para la micropropagación es el uso de nudos, la desinfección de estos explanes no se encuentra definida, el medio de cultivo para el establecimiento de nudos que dio el mejor resultado fue el medio de Gamborg o B5, suplementado con 1.5 mg/l de ANA

Selection bias: neighbourhood controls and controls selected from those presenting to a Health Unit in a case control study of efficacy of BCG revaccination.

BACKGROUND: In most case control studies the hardest decision is the choice of the control group, as in the ideal control group the proportion exposed is the same as in the population that produced the cases. METHODS: A comparison of two control groups in a case control study of the efficacy of BCG revaccination. One group was selected from subjects presenting to the heath unit the case attended for routine prevention and care; the second group was selected from the neighbourhood of cases. All Health Units from which controls were selected offered BCG revaccination. Efficacy estimated in a randomized control trial of BCG revaccination was used to establish that the neighbourhood control group was the one that gave unbiased results. RESULTS: The proportion of controls with scars indicating BCG revaccination was higher among the control group selected from Health Unit attenders than among neighbourhood controls. This excess was not removed after control for social variables and history of exposure to tuberculosis, and appears to have resulted from the fact that people attending the Health Unit were more likely to have been revaccinated than neighbourhood controls, although we can not exclude an effect of other unmeasured variables. CONCLUSION: In this study, controls selected from people presenting to a Health Unit overrepresented exposure to BCG revaccination. Had the results from the HU attenders control group been accepted this would have resulted in overestimation of vaccine efficacy. When the exposure of interest is offered in a health facility, selection of controls from attenders at the facility may result in over representation of exposure in controls and selection bias

D’Agents: Security in a Multiple-Language, Mobile-Agent System

Abstract. Mobile-agent systems must address three security issues: protecting an individual machine, protecting a group of machines, and protecting an agent. In this chapter, we discuss these three issues in the context of D’Agents, a mobile-agent system whose agents can be written in Tcl, Java and Scheme. (D’Agents was formerly known as Agent Tcl.) First we discuss mechanisms existing in D’Agents for protecting an individual machine: (1) cryptographic authentication of the agent’s owner, (2) resource managers that make policy decisions based on the owner’s identity, and (3) secure execution environments for each language that enforce the decisions of the resource managers. Then we discuss our planned market-based approach for protecting machine groups. Finally we consider several (partial) solutions for protecting an agent from a malicious machine.