The impact of the new Earth gravity models on the measurement of the Lense-Thirring effect

In this paper we use, in a preliminary way, the recently released EIGEN2 Earth gravity model, which is based on six months of data of CHAMP only, in order to reassess the systematic error due to the mismodelling in the even zonal harmonics of geopotential in the LAGEOS-LAGEOS II Lense-Thirring experiment involving the nodes of both the LAGEOS satellites and the perigee of LAGEOS II. The first results from the GGM01C Earth gravity model including the first GRACE data are very promising.Comment: LaTeX, 15 pages, no figures, 4 tables. To appear in General Relativity and Gravitatio

The Lunar Roving Vehicle: Historical perspective

As NASA proceeds with its studies, planning, and technology efforts in preparing for the early twenty-first century, it seems appropriate to reexamine past programs for potential applicability in meeting future national space science and exploration goals and objectives. Both the National Commission on Space (NCOS) study and NASA's 'Sally Ride study' suggest future programs involving returning to the Moon and establishing man's permanent presence there, and/or visiting the planet Mars in both the unmanned and manned mode. Regardless of when and which of these new bold initiatives is selected as our next national space goal, implementing these potentially new national thrusts in space will undoubtedly require the use of both manned and remotely controlled roving vehicles. Therefore, the purpose of this paper is to raise the consciousness level of the current space exploration planners to what, in the early 1970s, was a highly successful roving vehicle. During the Apollo program the vehicle known as the Lunar Roving Vehicle (LRV) was designed for carrying two astronauts, their tools, and the equipment needed for rudimentary exploration of the Moon. This paper contains a discussion of the vehicle, its characteristics, and its use on the Moon. Conceivably, the LRV has the potential to meet some future requirements, either with relatively low cost modifications or via an evolutionary route. This aspect, however, is left to those who would choose to further study these options

Positive and negative regulation of angiogenesis by soluble vascular endothelial growth factor receptor-1

Vascular endothelial growth factor receptor (VEGFR)-1 exists in different forms, derived from alternative splicing of the same gene. In addition to the transmembrane form, endothelial cells produce a soluble VEGFR-1 (sVEGFR-1) isoform, whereas non-endothelial cells produce both sVEGFR-1 and a different soluble molecule, known as soluble fms-like tyrosine kinase (sFlt)1-14. By binding members of the vascular endothelial growth factor (VEGF) family, the soluble forms reduce the amounts of VEGFs available for the interaction with their transmembrane receptors, thereby negatively regulating VEGFR-mediated signaling. In agreement with this activity, high levels of circulating sVEGFR-1 or sFlt1-14 are associated with different pathological conditions involving vascular dysfunction. Moreover, sVEGFR-1 and sFlt1-14 have an additional role in angiogenesis: they are deposited in the endothelial cell and pericyte extracellular matrix, and interact with cell membrane components. Interaction of sVEGFR-1 with α5β1 integrin on endothelial cell membranes regulates vessel growth, triggering a dynamic, pro-angiogenic phenotype. Interaction of sVEGFR-1/sFlt1-14 with cell membrane glycosphingolipids in lipid rafts controls kidney cell morphology and glomerular barrier functions. These cell-matrix contacts represent attractive novel targets for pharmacological intervention in addition to those addressing interactions between VEGFs and their receptors

Demonstration of GMPLS-controlled device power management for next generation green optical networks

We propose GMPLS protocol enhancements enabling dynamic power state management of optoelectronic network devices for setup-time-aware differentiated connection provisioning. Daily energy savings of 56% are demonstrated in a Pan-European-like network compared to always on scenarios.Postprint (published version

La Universidad Nacional de Mar del Plata y los emprendimientos productivos de la economía social: repensando desde donde actuar

Durante la post convertibilidad, los emprendimientos productivos de la economía social en Argentina encuentran, las condiciones propicias (tipo de política cambiaria, sustitución de las importaciones, Ley Nº 25085, Ley Nº 26117, diferentes planes Nacionales) para su desarrollo; creándose relaciones verticales y horizontales que facilitan la acumulación de valor agregado permitiendo la consolidación de la industria nacional. Cambios internos en la gestión política de la Facultad de Ciencias Económicas y Sociales UNMDP (2004-2009), posibilitaron la "apertura" hacia otras formas de vinculación con la sociedad. El Grupo de Extensión "Acompañando a emprendedores" (Director Lic Morea); forma parte de esta política de extensión, que entiende y aborda a la economía social como un fenómeno complejo y multicausal que requiere de intervenciones polifónicas.Fil: Morea, Francisco. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Meschini, Paula Andrea. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Morea, Soledad. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina

Análisis del comportamiento al ahuellamiento de diferentes mezclas en los ensayos de rueda cargada según normas bs 598-110 y cen 12697-22

El ensayo de rueda cargada ha sido reconocido como una herramienta importante para definir el desempeño de las mezclas asfálticas respecto a su resistencia al ahuellamiento. En Argentina existe mucha experiencia con este ensayo siguiendo la norma BS 598 part 110 y actualmente también con la norma CEN 12697-22. No existe en Argentina normativa que especifique el ensayo de rueda cargada y los parámetros de evaluación para el ensayo, solo existe recomendaciones para su realización según alguna de las normas mencionadas con el propósito de obtener una base de datos. Anteriormente a nivel nacional e internacional se han comparado ambos métodos de ensayo los que servirán de referencia para este estudio que tiene por objetivo comparar el comportamiento al ahuellamiento en los ensayo de rueda cargada según las normativas mencionadas sobre las diferentes tipos de mezclas asfálticas. Se estudiaron diferentes condiciones como ser distintas temperaturas de ensayo y variando condiciones volumétricas de diseño de las mezclas Se profundiza y discute aquí estudios realizados anteriormente en relación a parámetros obtenidos de ambos métodos (BS 598 y CEN 12697-22). De esta manera se brinda una herramienta para comparar resultados y de ser posible permitir definir a futuro una especificación y parámetros de análisis.The Wheel Tracking test has been recognized as an important tool to define the performance of asphalt mixtures for rutting resistance. In Argentina this test is typically performed, according to BS 598 part 110 and recently also with the CEN standard 12697-22. There are in Argentina no rules specifying the Wheel Tracking test and its assessment parameters, but only recommendations for its implementation by any of the above standards in order to obtain a database. In the past, at national and international level, both test methods have been compared; this serves as a reference for this study aimed at comparing the rutting behavior in the Wheel Tracking test on different types of asphalt mixtures, according to the mentioned regulations. Different test conditions are tested in this work, such as temperatures and volumetric conditions of mix design. Here are deepened and discussed some previous studies above parameters obtained from both methods (BS 598 and CEN 12697-22). In this way it is provided a tool to compare results and if possible allow to define a future specification and analysis parameters

Advanced research and technology programs for advanced high-pressure oxygen-hydrogen rocket propulsion

A research and technology program for advanced high pressure, oxygen-hydrogen rocket propulsion technology is presently being pursued by the National Aeronautics and Space Administration (NASA) to establish the basic discipline technologies, develop the analytical tools, and establish the data base necessary for an orderly evolution of the staged combustion reusable rocket engine. The need for the program is based on the premise that the USA will depend on the Shuttle and its derivative versions as its principal Earth-to-orbit transportation system for the next 20 to 30 yr. The program is focused in three principal areas of enhancement: (1) life extension, (2) performance, and (3) operations and diagnosis. Within the technological disciplines the efforts include: rotordynamics, structural dynamics, fluid and gas dynamics, materials fatigue/fracture/life, turbomachinery fluid mechanics, ignition/combustion processes, manufacturing/producibility/nondestructive evaluation methods and materials development/evaluation. An overview of the Advanced High Pressure Oxygen-Hydrogen Rocket Propulsion Technology Program Structure and Working Groups objectives are presented with highlights of several significant achievements

Analysis of rutting behaviour of different mixtures in wheel tracking tests according to BS 598-110 and CEN 12697-22 standard

El ensayo de rueda cargada ha sido reconocido como una herramienta importante para definir el desempeño de las mezclas asfálticas respecto a su resistencia al ahuellamiento. En Argentina existe mucha experiencia con este ensayo siguiendo la norma BS 598 part 110 y actualmente también con la norma CEN 12697-22. No existe en Argentina normativa que especifique el ensayo de rueda cargada y los parámetros de evaluación para el ensayo, solo existe recomendaciones para su realización según alguna de las normas mencionadas con el propósito de obtener una base de datos. Anteriormente a nivel nacional e internacional se han comparado ambos métodos de ensayo los que servirán de referencia para este estudio que tiene por objetivo comparar el comportamiento al ahuellamiento en los ensayo de rueda cargada según las normativas mencionadas sobre las diferentes tipos de mezclas asfálticas. Se estudiaron diferentes condiciones como ser distintas temperaturas de ensayo y variando condiciones volumétricas de diseño de las mezclas Se profundiza y discute aquí estudios realizados anteriormente en relación a parámetros obtenidos de ambos métodos (BS 598 y CEN 12697-22). De esta manera se brinda una herramienta para comparar resultados y de ser posible permitir definir a futuro una especificación y parámetros de análisis.The Wheel Tracking test has been recognized as an important tool to define the performance of asphalt mixtures for rutting resistance. In Argentina this test is typically performed, according to BS 598 part 110 and recently also with the CEN standard 12697-22. There are in Argentina no rules specifying the Wheel Tracking test and its assessment parameters, but only recommendations for its implementation by any of the above standards in order to obtain a database. In the past, at national and international level, both test methods have been compared; this serves as a reference for this study aimed at comparing the rutting behavior in the Wheel Tracking test on different types of asphalt mixtures, according to the mentioned regulations. Different test conditions are tested in this work, such as temperatures and volumetric conditions of mix design. Here are deepened and discussed some previous studies above parameters obtained from both methods (BS 598 and CEN 12697-22). In this way it is provided a tool to compare results and if possible allow to define a future specification and analysis parameters.Fil: Morea, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Gobernacion. Comision de Investigaciones Cientificas. Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica; Argentin

Melanocyte proliferation in wounded skin in vitro: a histological and immunohistochemical analysis

Wounding of skin initiates a complex series of overlapping cellular events that culminates in the formation of a scar. The negative consequence of most cutaneous scars is the lack of adequate repigmentation of the neoepidermis. In order to effect successful wound healing by restoration of effective skin barrier function, keratinocytes must proliferate and migrate to cover the gap created by the wound in an efficient and timeous manner. Melanocytes are not thought to actively participate in wound repair and closure, since they are primarily responsible for maintenance of normal skin pigmentation. Mechanisms of keratinocyte migration during the re-epithelialisation phase of cutaneous wound healing have been well documented. However, it is not clear how melanocytes contribute to neoepidermis formation and repigmentation. Provision of an optimal epidermal milieu would enable restoration of pigmentation of cutaneous scars for a satisfactory cosmetic outcome. This dissertation contributes to the understanding of melanocyte participation and proliferation during re-epithelialisation of skin using an in vitro skin organ culture model of wound healing. To determine whether the culture model used in this study was reliable, skin explants were cultured over a period of 12 days, fixed and processed for histological analysis. By measuring the lengths of the developing epidermal tongues, it was noted that epiboly was the initial event that occurred at the wound edges. After day two of culture, growth of the epithelial tongues was observed from the wound edges, which peaked at day five. The length of the epidermal tongues remained constant for the remaining culture period up to day twelve, at which stage complete wound closure was observed in some samples. Histological analysis of the tongues revealed that the cultured skin remained viable for the duration of culture period. To establish to what extent keratinocyte proliferation contributed to the growth of the tongues, immunohistochemical staining using the proliferation marker, Ki67, was used. Results show that after an initial lag phase, with no detectable cell proliferation at the wound edges, dividing keratinocytes were seen at day two post-wounding. The number of dividing keratinocytes peaked at day five, where after the numbers remained constant until day twelve of culture. This result supports the validity of the culture model. To uncover whether melanocytes re-enter the neoepidermis during wound during re-epithelialisation, the number of melanocytes per unit of basement membrane was determined using immunohistochemical staining. The melanocyte-specific marker, MART-1/MelanA, was used in conjunction with the proliferation marker, Ki-67, in an optimised dual immunolabelling protocol {Petersen, 2012 #397} to establish whether melanocytes proliferate during re-epithelialisation of wounds. Melanocytes along the basal layer of the epithelial tongues and in the normal epidermis were located and counted. Basal melanocytes (MelanA+) were seen from day two onwards in the normal epidermis and from day five onwards in the developing epidermal tongues. However, at days ten and twelve of the culture period. dividing melanocytes (Ki67+/MelanA+) were seen in the epidermis in locations: proximal to the wound area, at the wound edge and in the developing tongues. This result suggests that melanocyte entry into the wound is delayed until after keratinocyte proliferation has brought about the beginning of neoepidermis formation and growth. This result also demonstrates the proliferation potential of differentiated melanocytes and that de-differentiation of melanocytes can occur under favourable culture conditions as can be seen in this culture model