The ATS-6 power system: Hardware implementation and orbital performance

The Applications Technology Satellite-6 power system, a shunt-boost configuration, uses partial shunt regulation of the solar array and a boost regulator for control of battery power. Regulation is provided for three different operating modes: shunt, charge, and boost. This configuration achieves the highest efficiency of power transfer from the solar array to the loads. The excellent dynamic regulation and low output impedance of the power system virtually eliminated the problem of subsystem interactions on the power bus due to conducted interference from load current fluctuations. The performance of the power system continues to be excellent. The solar array degradation (18.5 percent) was less than the specified 20 percent in two years in spite of extreme cycling from -160 C to 60 C. A unique battery cycling regime of discharges varying from 5 percent to 60 percent daily is being encountered. During the second year, noneclipse discharges have occurred twice a day to depths of 35 percent and 45 percent. Battery performance was good with only a small decrease in end-of-discharge voltage. A recent test to evaluate capacity gave 12.4 AH (83% of the nominal capacity of 15 AH) after over 1400 battery discharge cycles. A small increase in the end-of-charge voltage has recently occurred necessitating a change in the charge regime to achieve full charge conditions

Induced Cell Proliferation Initiated by Roxarsone (ROX) is not Sufficient to Prevent Acrylamide Impairments in Beas-2B Cells.

Natural environmental contaminants and xenobiotic compounds consumed by humans are likely to be deleterious to human health. This study evaluates the effects of the organoarsenic compound roxarsone and the organic compound acrylamide on BEAS-2B cells. Arsenic occurs naturally in the environment in inorganic and organic forms. Inorganic arsenics are carcinogenic to humans. Organic arsenics (organoarsenics) are less toxic, yet their level of toxicity cannot be ignored. Roxarsone (4-hydroxy-3-nitrobenzenearsonate) is a compound used as a poultry feed additive and antimicrobial agent. It promotes cell proliferation and possesses angiogenesis properties. Roxarsone (ROX) can be found in chicken breast meat; along with a metabolite of ROX, thiolated roxarsone, which is more toxic than Roxarsone. Acrylamide is used in the manufacturing of paper, dye, and industrial products. It is also found in starchy food cooked at high temperatures. The body can be simultaneously exposed to ROX and acrylamide through food consumption. Acrylamide is known to cause cell damage, impair cell viability, and it affects cell proliferation. Experimental findings showed that 3.5 mM acrylamide destroys about half the population of BEAS-2B cells. Since acrylamide has deleterious effects on cells, it may be possible for ROX which stimulates cell proliferation, to ameliorate the deleterious effects of acrylamide. Previous studies showed that 10 µM Roxarsone induces cell proliferation. The specific aim of this study to demonstrate that the stimulation of BEAS-2B cell proliferation by 10 µM Roxarsone is not sufficient to protect the cells from damage induced by acrylamide. The first aim of this study is to demonstrate that treatment of BEAS-2B cells with ROX followed by treatment with acrylamide will alter cell morphology. The working hypothesis is that treatment of BEAS-2B cells with 10 µM ROX followed by 3.5 mM acrylamide will cause crenation, causing changes in cell morphology. The second aim of this study is to demonstrate that changes in cell morphology due to crenation will alter the PI3K/AKT pathway. The working hypothesis is that change in cell morphology will alter the proper functioning of genetic material and cellular responses, which is likely to destroy the PI3K/AKT cell survival pathway. Observation of cell morphology in response to ROX show that ROX induced cell proliferation in BEAS-2B cells with no morphological changes observed. Treatment of BEAS-2B cells with 10 µM ROX followed by 3.5 mM acrylamide changed cell morphology, which suggests that acrylamide is responsible for changes in cell morphology. Acrylamide-induced cell shrinkage and increased cell death were observed in treated BEAS-2B cells. ROX induced cell proliferation and caused significant upregulation of Ak strain transforming (AKT) levels after 24 hours of exposure. Cell proliferation stopped when the cells reached their maximum confluency at 48 hours. AKT and downstream genes in the PI3K/AKT pathway were analyzed in BEAS-2B cells treated with Roxarsone, or a combination of Roxarsone and acrylamide

Satellite Servicing in the Space Station Era

Repair and serv1c1ng of orbiting satellites in the Space Station era will realize significant enhancements to the capabilities available to date. The first on-orbit repair of an orbiting satellite was demonstrated in 1972 on the Skylab mission using makeshift tools, procedures, and Extravehicular Activity (EVA) techniques. Subsequently, in 1984, the repair and resultant extension of the Solar Maximum Mission (SMM) took full advantage of the spacecraft\u27s having been designed at the outset to be repaired and modified on orbit. Although this mission, among others performed by the Space Transportation System (STS) (Westar 6, Palapa 8-2, and Leasat F3), testified to the fact that much progress had been made in the on-orbit repair and servicing of satellites, it also served to highlight the areas in which considerable improvement and technology development were needed. The Space Station capabilities for on-orbit servicing will serve to provide these improvements and technology advances. By expanding on the servicing experience and capabilities provided directly by the STS, the Space Station will significantly enhance mission objectives of long-duration scientific missions, not only by repair and consumable replenishment, but also by the addition and replacement of scientfic instruments with upgraded versions. Major observatory missions such as the Hubble Space Telescope (HST), the Gamma Ray Observatory (GRO), and the Advanced X-ray Astronomical Facility (AXAF) will be among the beneficiaries of this new, enhanced capability. This paper will describe the satellite servicing capabilities planned for the Space Station

Planar Element Alignment System

Precise alignment to the micron level is a necessity for microfluidic/micromechanical devices to function as designed. Because of this, a micro-alignment device was commissioned by Professor Hans Mayer on behalf of the Cal Poly Microfluidics Laboratory. Prototype creation was bounded by a set of requirements including, ability to align PDMS & Silicon wafer halves to ± 10 microns, total process speed of three minutes, and total budget of $3000. Some major design hurdles included an ability to verify alignment, possible non-planar alignment pieces, and an inability to contact any point on the face of the alignment pieces after bonding treatment. These were addressed by using clear, acrylic vacuum chucks and two digital cameras. That way, alignment could be verified visually with the camera and see-through vacuum chuck and the vacuum chuck would be able to secure the alignment pieces while only contacting a single face. The possible non-planar surface of the alignment pieces was determined to be a concern but will be assessed whether it needed addressing during testing. Manufacturing/sourcing of each piece of the prototype went generally smoothly. One delayed piece made it unable to fully assemble the prototype for a final verification test. However, the stages purchased are more than capable to meet the design alignment requirements and the total budget was more than met. The final design requirement of a total process time of under three minutes unfortunately remains untested

Violence and under-reporting: Learning disability nursing and the impact of environment, experience and banding

This is the authors' version of an article published in the Journal of Clinical Nursing. The definitive version is available at www3.interscience.wiley.comThe study explores the implications of a survey into the discrepancy between actual and reported incidents of violence, perpetrated by service users, within the learning disability division of one mental health NHS Trust. Violence within the NHS continues to constitute a significant issue, especially within mental health and learning disability services where incidence remains disproportionately high despite the context of zero tolerance. A whole-population survey of 411 nurses working within a variety of settings within the learning disability division of one mental health NHS Trust. A questionnaire was administered to learning disability nursing staff working in community, respite, residential, assessment and treatment and medium secure settings, yielding a response rate of approximately 40%. There were distinct differences in the levels of violence reported within specific specialist services along with variation between these areas according to clinical environment, years of experience and nursing band. The study does not support previous findings whereby unqualified nurses experienced more incidents of violence than qualified nurses. The situation was less clear, complicated by the interrelationship between years of nursing experience, nursing band and clinical environment. The conclusions suggest that the increased emphasis on reducing violent incidents has been fairly successful with staff reporting adequate preparation for responding to specific incidents and being well supported by colleagues, managers and the organisation. The differences between specific clinical environments, however, constituted a worrying finding with implications for skill mix and staff education. The study raises questions about the relationship between the qualified nurse and the individual with a learning disability in the context of violence and according to specific circumstances of care delivery. The relationship is clearly not a simple one, and this group of nurses’ understanding and expectations of tolerance requires further research; violence is clearly never acceptable, but these nurses appear reluctant to condemn and attribute culpability

Practice Leadership at the front line in supporting people with intellectual disabilities and challenging behaviour: a qualitative study of registered managers of community-based, staffed group homes.

Background The front-line management role in services for people with intellectual disabilities remains rather under-researched. The aim of this study was to examine the experiences of registered managers in services for adults with intellectual disability who exhibit challenging behaviour. Method Interviews, primarily focussed upon staff practice, were conducted with 19 managers of staffed group homes in SE England. Transcripts were analysed using interpretive phenomenological analysis. Results Five groups of themes emerged: monitoring staff performance, supporting new ways of working, shaping staff performance, influence of external and employing agencies, and importance of participants' personal values and experiences. Conclusion The themes identified contribute to a conceptual framework for thinking about front-line management/practice leadership. The limitations, and potential implications, of the findings are discussed

Reflections on Positive Behavior Support

El Apoyo Conductual Positivo (ACP) representa un movimiento científico que une dos líneas de trabajo, una bajo el Análisis Conductual Aplicado y otra de carácter teórico que recoge valores y conceptos descritos y desarrollados en el campo de las discapacidades intelectuales. En sus inicios fue una intervención ante las conductas problemáticas con procedimientos positivos en contraposición al abuso de prácticas negativas (aversivas). Paso a paso, se comprobó que las técnicas positivas necesitaban ser aplicadas de forma preventiva y proactiva para educar y reforzar habilidades cuya equivalencia funcional fuera la misma que motivaba las conductas problemáticas. Por último, se introdujeron claves de la línea teórica y del contexto, como calidad, normalización, valores, etcétera. Hoy el ACP ha trascendido su primer cometido y es una forma de trabajar en cualquier servicio independientemente de que haya o no conductas problemáticas, más aún, está siendo aplicado en contextos escolares,judiciales y de tercera edad. Ahora bien, el ACP tiene bastantes desafíos, entre otros la definición operativa de los conceptos que caen bajo la vertiente teórica y su desarrollo discriminativo. Por otra parte, para algunos, el abuso del discurso en relación con la falta de concreción operativa y el uso de conceptos indiscutibles (que nadie pondría en duda, como el de positivo) representa un peligro a la credibilidad científica del ACP

A tetracationic porphyrin with dual anti-prion activity

Prions are deadly infectious agents made of PrPSc, a misfolded variant of the cellular prion protein (PrPC) which self-propagates by inducing misfolding of native PrPC. PrPSc can adopt different pathogenic conformations (prion strains), which can be resistant to potential drugs, or acquire drug resistance, hampering the development of effective therapies. We identified Zn(II)-BnPyP, a tetracationic porphyrin that binds to distinct domains of native PrPC, eliciting a dual anti-prion effect. Zn(II)-BnPyP binding to a C-terminal pocket destabilizes the native PrPC fold, hindering conversion to PrPSc; Zn(II)-BnPyP binding to the flexible N-terminal tail disrupts N- to C-terminal interactions, triggering PrPC endocytosis and lysosomal degradation, thus reducing the substrate for PrPSc generation. Zn(II)-BnPyP inhibits propagation of different prion strains in vitro, in neuronal cells and organotypic brain cultures. These results identify a PrPC-targeting compound with an unprecedented dual mechanism of action which might be exploited to achieve anti-prion effects without engendering drug resistance

Revisión de diferentes enfoques de evaluación y tratamiento de los problemas de comportamiento

El presente documento se centra en disminuir conductas que, quizás, es algo más complejo ya que los profesionales deben adquirir mayor responsabilidad debido a las técnicas que se pueden utilizar. Dirigido a maestros, ayudantes, personal institucional, diseñadores de programas, miembros de los comités de manejo conductual o comités de procedimientos restrictivos. Se centra en personas con retraso mental severo y profundo ya que hay menos textos disponibles para tratarles que con niveles más altos de discapacidad. Los procedimientos se presentan de acuerdo con el Modelo de Tratamiento Menos Restrictivo que se ha desarrollado para proteger las libertades civiles de las personas con retraso en el desarrollo