Technology Directions for the 21st Century, volume 1

For several decades, semiconductor device density and performance have been doubling about every 18 months (Moore's Law). With present photolithography techniques, this rate can continue for only about another 10 years. Continued improvement will need to rely on newer technologies. Transition from the current micron range for transistor size to the nanometer range will permit Moore's Law to operate well beyond 10 years. The technologies that will enable this extension include: single-electron transistors; quantum well devices; spin transistors; and nanotechnology and molecular engineering. Continuation of Moore's Law will rely on huge capital investments for manufacture as well as on new technologies. Much will depend on the fortunes of Intel, the premier chip manufacturer, which, in turn, depend on the development of mass-market applications and volume sales for chips of higher and higher density. The technology drivers are seen by different forecasters to include video/multimedia applications, digital signal processing, and business automation. Moore's Law will affect NASA in the areas of communications and space technology by reducing size and power requirements for data processing and data fusion functions to be performed onboard spacecraft. In addition, NASA will have the opportunity to be a pioneering contributor to nanotechnology research without incurring huge expenses

Determination of uric acid in serum using isotachophoresis

An operational system is described for the isotachophoretic determination of uric acid in serum, making use of column coupling. The method has been compared with a standard enzymatic procedure. With the present technique small amounts of serum (ca. 3 μl) can be applied without any pretreatment. Urate recovery was 99.0–100.5%. Under the non-physiological measuring conditions used, 12–28% of control serum uric acid was bound to macromolecules of molecular weight exceeding 25,000. The day-to-day variations of the isotachophoretic procedure were smaller than those of the enzymatic method, whereas standard deviations were comparable. The isotachophoretic procedure is less influenced by certain metabolites

Technology Directions for the 21st Century

The Office of Space Communications (OSC) is tasked by NASA to conduct a planning process to meet NASA's science mission and other communications and data processing requirements. A set of technology trend studies was undertaken by Science Applications International Corporation (SAIC) for OSC to identify quantitative data that can be used to predict performance of electronic equipment in the future to assist in the planning process. Only commercially available, off-the-shelf technology was included. For each technology area considered, the current state of the technology is discussed, future applications that could benefit from use of the technology are identified, and likely future developments of the technology are described. The impact of each technology area on NASA operations is presented together with a discussion of the feasibility and risk associated with its development. An approximate timeline is given for the next 15 to 25 years to indicate the anticipated evolution of capabilities within each of the technology areas considered. This volume contains four chapters: one each on technology trends for database systems, computer software, neural and fuzzy systems, and artificial intelligence. The principal study results are summarized at the beginning of each chapter

Volatile‐mediated interactions with surface‐associated microbes: A parallelism between phyllosphere of plants and eco‐chemosphere of seaweeds

1. Both in terrestrial and aquatic realms, organisms communicate and interact with each other via volatile and non-volatile infochemicals. Terrestrial plants and seaweeds, known as prolific producers of volatiles, harbour a plethora of microbes on their surfaces like phyllosphere of plant leaves and eco-chemosphere of seaweeds, respectively, where complex ecological interactions are regulated through infochemicals. 2. Although plant leaf volatiles have been well-studied for their ecological functions in mediating microbial interactions, seaweed volatiles have been mostly investigated for their roles in climate regulation and with regard to climate change research. However, seaweed volatiles appear to be related to terrestrial plant volatiles both in terms of chemistry and ecology. 3. Synthesis. Evidence supports that seaweed volatiles can have important ecological functions in mediating interactions with microbes on their surface, just like plant leaf volatiles. Based on the existing vast literature on ecological interactions mediated by plant volatiles at phyllosphere and on the very few works on ecological roles of seaweed volatiles at eco-chemosphere, we advocate for the detailed investigation of volatile-mediated interactions regulating microbial colonisation processes on seaweed surfaces. Although of great ecological importance, this new field of research has remained largely unexplored. Thus, we also set directions for future research programs investigating the roles of seaweed volatiles at seaweed–microbe interface

Technology Directions for the 21st Century

New technologies will unleash the huge capacity of fiber-optic cable to meet growing demands for bandwidth. Companies will continue to replace private networks with public network bandwidth-on-demand. Although asynchronous transfer mode (ATM) is the transmission technology favored by many, its penetration will be slower than anticipated. Hybrid networks - e.g., a mix of ATM, frame relay, and fast Ethernet - may predominate, both as interim and long-term solutions, based on factors such as availability, interoperability, and cost. Telecommunications equipment and services prices will decrease further due to increased supply and more competition. Explosive Internet growth will continue, requiring additional backbone transmission capacity and enhanced protocols, but it is not clear who will fund the upgrade. Within ten years, space-based constellations of satellites in Low Earth orbit (LEO) will serve mobile users employing small, low-power terminals. 'Little LEO's' will provide packet transmission services and geo-position determination. 'Big LEO's' will function as global cellular telephone networks, with some planning to offer video and interactive multimedia services. Geosynchronous satellites also are proposed for mobile voice grade links and high-bandwidth services. NASA may benefit from resulting cost reductions in components, space hardware, launch services, and telecommunications services

Steekmuggen in de Peelvenen

“Vernatting leidt tot een muggeneldorado”. Krantenberichten met dergelijke koppen kom je de laatste jaren vaak tegen. Vernatting van natuurgebieden of waterberging leidt bij omwonenden namelijk tot zorg over muggenoverlast. Zo ook rondom de Peelvenen op de grens van Limburg en Noord-Brabant waar de beheerder met maatregelen probeert om de sterke waterstandsschommelingen tussen winter en zomer te verminderen. De vraag is of er een direct verband is tussen vernatting en steekmuggen, en zo ja: hoe kunnen we die muggenoverlast voorkomen

Results from the CERN pilot CLOUD experiment

During a 4-week run in October–November 2006, a pilot experiment was performed at the CERN Proton Synchrotron in preparation for the Cosmics Leaving OUtdoor Droplets (CLOUD) experiment, whose aim is to study the possible influence of cosmic rays on clouds. The purpose of the pilot experiment was firstly to carry out exploratory measurements of the effect of ionising particle radiation on aerosol formation from trace H2SO4 vapour and secondly to provide technical input for the CLOUD design. A total of 44 nucleation bursts were produced and recorded, with formation rates of particles above the 3 nm detection threshold of between 0.1 and 100 cm−3 s−1, and growth rates between 2 and 37 nm h−1. The corresponding H2SO4 concentrations were typically around 106 cm−3 or less. The experimentally-measured formation rates and H2SO4 concentrations are comparable to those found in the atmosphere, supporting the idea that sulphuric acid is involved in the nucleation of atmospheric aerosols. However, sulphuric acid alone is not able to explain the observed rapid growth rates, which suggests the presence of additional trace vapours in the aerosol chamber, whose identity is unknown. By analysing the charged fraction, a few of the aerosol bursts appear to have a contribution from ion-induced nucleation and ion-ion recombination to form neutral clusters. Some indications were also found for the accelerator beam timing and intensity to influence the aerosol particle formation rate at the highest experimental SO2 concentrations of 6 ppb, although none was found at lower concentrations. Overall, the exploratory measurements provide suggestive evidence for ion-induced nucleation or ion-ion recombination as sources of aerosol particles. However in order to quantify the conditions under which ion processes become significant, improvements are needed in controlling the experimental variables and in the reproducibility of the experiments. Finally, concerning technical aspects, the most important lessons for the CLOUD design include the stringent requirement of internal cleanliness of the aerosol chamber, as well as maintenance of extremely stable temperatures (variations below 0.1 _C)

Changes in behavioural synchrony during dog-assisted therapy for children with autism spectrum disorder and children with Down syndrome

BACKGROUND: Dog-assisted therapy (DAT) is hypothesized to help children with autism spectrum disorder (ASD) and Down syndrome (DS). METHODS: The present authors compared synchronous movement patterns of these children (n = 10) and their therapy dogs during the first and last session of a DAT programme, and their post-therapy changes in emotional and behavioural problems. RESULTS: The present authors found a significant increase in synchrony between child and therapy dog over time. Exploratory analyses suggest more synchrony between children with ASD and their therapy dogs, compared to the children with DS. CONCLUSIONS: This study is the first to test the synchrony hypothesis, shedding light upon a mechanism that may underlie the effect of DAT and how this may be different for children with ASD and DS