25,881 research outputs found
Four-dimensional worldwide atmospheric models: ANYPT and ANYRG
Computer programs read magnetic-tape data bases and computer meteorological profiles for any position, time, and height (from zero to 25 km). System assists in analyses of distortion of information obtained from aircraft-mounted or spacecraft-mounted electromagnetic sensors
Recommended from our members
NeuroEVs: Characterizing Extracellular Vesicles Generated in the Neural Domain.
Intercellular communication has recently been shown to occur via transfer of cargo loaded within extracellular vesicles (EVs). Present within all biofluids of the body, EVs can contain various signaling factors, including coding and noncoding RNAs (e.g., mRNA, miRNA, lncRNA, snRNA, tRNA, yRNA), DNA, proteins, and enzymes. Multiple types of cells appear to be capable of releasing EVs, including cancer, stem, epithelial, immune, glial, and neuronal cells. However, the functional impact of these circulating signals among neural networks within the brain has been difficult to establish given the complexity of cellular populations involved in release and uptake, as well as inherent limitations of examining a biofluid. In this brief commentary, we provide an analysis of the conceptual and technical considerations that limit our current understanding of signaling mediated by circulating EVs relative to their impact on neural function
The Evolution of Overconfidence
Confidence is an essential ingredient of success in a wide range of domains
ranging from job performance and mental health, to sports, business, and
combat. Some authors have suggested that not just confidence but
overconfidence-believing you are better than you are in reality-is advantageous
because it serves to increase ambition, morale, resolve, persistence, or the
credibility of bluffing, generating a self-fulfilling prophecy in which
exaggerated confidence actually increases the probability of success. However,
overconfidence also leads to faulty assessments, unrealistic expectations, and
hazardous decisions, so it remains a puzzle how such a false belief could
evolve or remain stable in a population of competing strategies that include
accurate, unbiased beliefs. Here, we present an evolutionary model showing
that, counter-intuitively, overconfidence maximizes individual fitness and
populations will tend to become overconfident, as long as benefits from
contested resources are sufficiently large compared to the cost of competition.
In contrast, "rational" unbiased strategies are only stable under limited
conditions. The fact that overconfident populations are evolutionarily stable
in a wide range of environments may help to explain why overconfidence remains
prevalent today, even if it contributes to hubris, market bubbles, financial
collapses, policy failures, disasters, and costly wars.Comment: Supplementary Information include
Guidance methods for low-thrust space vehicles Cumulative progress report, 1 Jan. 1969 - 31 Jan. 1970
Guidance and control schemes for optimal low-thrust Earth-Mars transfer mission
Topological code Autotune
Many quantum systems are being investigated in the hope of building a
large-scale quantum computer. All of these systems suffer from decoherence,
resulting in errors during the execution of quantum gates. Quantum error
correction enables reliable quantum computation given unreliable hardware.
Unoptimized topological quantum error correction (TQEC), while still effective,
performs very suboptimally, especially at low error rates. Hand optimizing the
classical processing associated with a TQEC scheme for a specific system to
achieve better error tolerance can be extremely laborious. We describe a tool
Autotune capable of performing this optimization automatically, and give two
highly distinct examples of its use and extreme outperformance of unoptimized
TQEC. Autotune is designed to facilitate the precise study of real hardware
running TQEC with every quantum gate having a realistic, physics-based error
model.Comment: 13 pages, 17 figures, version accepted for publicatio
Impact of the Redheaded Pine Sawfly (Hymenoptera: Diprionidae) on Young Red Pine Plantations
The ecology of the redheaded pine sawfly was studied relative to its impact on red pine plantations. An ecological model, which formed the basis for socioeconomic analysis, was constructed. Because the sawfly prefers trees under moisture stress, damage is most severe in stands growing on sand blows, where there is competition for moisture from bracken fern and hardwoods, and where soils are too moist, too shallow, or too compacted. Outbreaks also appear to be related to dry years. The sawfly has a variable impact on multiple-use values. Because it injures the least productive trees in a stand, timber is only indirectly affected. Small openings created by tree mortality after an outbreak may provide edge \u27Wildlife habitat. The sawfly has both negative and positive effects on recreationists, depending upon the type of recreation; it may be a nuisance to campers, but may positively influence hunting. Preventive sawfly management involves proper site selection for red pine
Quantum computing with nearest neighbor interactions and error rates over 1%
Large-scale quantum computation will only be achieved if experimentally
implementable quantum error correction procedures are devised that can tolerate
experimentally achievable error rates. We describe a quantum error correction
procedure that requires only a 2-D square lattice of qubits that can interact
with their nearest neighbors, yet can tolerate quantum gate error rates over
1%. The precise maximum tolerable error rate depends on the error model, and we
calculate values in the range 1.1--1.4% for various physically reasonable
models. Even the lowest value represents the highest threshold error rate
calculated to date in a geometrically constrained setting, and a 50%
improvement over the previous record.Comment: 4 pages, 8 figure
- …
