Networked VAX/LSI/CAMAC Data Acquisition System Development

Recent development of the Caltech data acquisition system installed in 1981, which runs on a VAX-11/750, a Peritek Q-bus network, LSI-11s, and CAMAC, is described. In this system, the DEC VMS and RT-11 operating systems are supported on the VAX "host" and LSI-11 "front-end" computers by a VMS device driver and network host program, and a bootable RT-11 device driver. Network "utility" and "control" programs provide general purpose support for communication between front-end and host software. Data acquisition software tools are provided for writing programs to run nuclear physics experiments. A system similar to Caltech's was installed at the University of Rochester in 1982. The network has been tested for speed and real-time response. After including all software overhead required by data acquisition, it was found that the system could transfer buffers and acknowledge their receipt at a net speed of 127 KB per second with a 35% load on the host computer. The network software is currently being rehosted on Ethernet hardware at Caltech in a multiple host - many front-end computer configuration. Compatibility with the current Peritek network software will be maintained

Preliminary spectral analysis of near-real-time radon data

Fast Fourier analysis of the near-real-time radon data collected since 1977 by the Caltech automated radon-thoron monitoring system has been carried out in order to determine if any characteristic frequency components are present that can be associated either with precursors to seismicity or with environmental factors. Preliminary results indicate that during "quiet" periods with low seismicity and no rainfall the spectral power is distributed as 1/f. Before four local earthquakes a departure from this 1/f behavior was observed at low frequency. During periods of heavy rainfall an increase in both low and high frequency power was observed. The spectral power of the large radon anomaly observed prior to the October 15, 1979 Imperial Valley earthquake was found to have a 1/f distribution but with power at all frequencies about four times greater than that of data from "quiet" periods

Relationship of the 1979 Southern California Radon Anomaly to a possible regional strain event

During the second half of 1979, anomalously high emanation of radon was recorded at two stations of the automated radon-thoron monitoring network operated by the W. K. Kellogg Radiation Laboratory of the California Institute of Technology. The two stations exhibiting major anomalies, Kresge and Dalton Canyon, are located approximately 30 km apart on the frontal fault system of the Transverse Ranges of southern California. At Kresge the anomaly began on June 21, 1979, and continued through December 1979. At Dalton Canyon the anomaly started about 3 weeks later and also continued through December 1979. At both sites the anomalous levels of radon decreased (but did not return entirely to normal values) shortly before October 15, 1979. During the week of October 15, 1979, a 6.6-M earthquake occurred about 290 km to the southeast of the two stations, and later in that week, earthquakes of magnitude 4.2 and 4.1 occurred at Malibu and Lytle Creek. The latter two events were within 60 km of the monitors. A radon-thoron monitor at Lytle Creek recorded no long-term anomaly but did record a sharp spikelike decrease in the radon level on October 13, 1979. Coincident with our observations of anomalous radon levels, other investigators have reported anomalies or suspected anomalies in several other geodetic, geophysical, and geochemical signals from the same general region. The rapid temporal development of several of the anomalies together with the large area over which they were observed suggests that a large-scale strain event took place which may have been responsible both for the widespread anomalies and for the seismicity that occurred in the region subsequent to the onset of the anomalies

Learning situated emotions

From the perspective of constructivist theories, emotion results from learning assemblies of relevant perceptual, cognitive, interoceptive, and motor processes in specific situations. Across emotional experiences over time, learned assemblies of processes accumulate in memory that later underlie emotional experiences in similar situations. A neuroimaging experiment guided participants to experience (and thus learn) situated forms of emotion, and then assessed whether participants tended to experience situated forms of the emotion later. During the initial learning phase, some participants immersed themselves in vividly imagined fear and anger experiences involving physical harm, whereas other participants immersed themselves in vividly imagined fear and anger experiences involving negative social evaluation. In the subsequent testing phase, both learning groups experienced fear and anger while their neural activity was assessed with functional magnetic resonance imaging (fMRI). A variety of results indicated that the physical and social learning groups incidentally learned different situated forms of a given emotion. Consistent with constructivist theories, these findings suggest that learning plays a central role in emotion, with emotion adapted to the situations in which it is experienced

Correlated radon and CO_2 variations near the San Andreas Fault

Correlations have been observed between groundwater radon and thoron concentrations and carbon dioxide discharges at the Lake Hughes station of the Caltech radon monitoring network. The Lake Hughes site is one of three radon monitoring stations located near the "big bend" segment of the San Andreas fault which began to record anomalous radon levels in August 1981. Two stations, Lake Hughes and Lytle Creek, recorded anomalous increases in radon while the third, Sky Forest, recorded an anomalous decrease. Several weeks after the onset of the anomaly, strongly correlated radon fluctuations began at Lake Hughes and Lytle Creek. These radon spikes also were found to be phase anti-correlated with barometric pressure fluctuations. Analyses of gas grab samples showed relatively high levels of CO_2 and ethylene in borehole air at Lake Hughes and Lytle Creek, while analyses of water samples showed relatively large increases in HCO_3^− at both sites. Isotopic analysis of one gas sample from Lake Hughes yielded a ^(13)C δ value of −22 ‰, which suggests that the CO_2 originates from the oxidation of organic material. The correlation in radon fluctuations at Lake Hughes and Lytle Creek and their common dependence on barometric pressure changes began shortly after the onset of the radon anomaly in August, and probably resulted from the simultaneous saturation of the water in these boreholes with carbon dioxide

Robust Online Hamiltonian Learning

In this work we combine two distinct machine learning methodologies, sequential Monte Carlo and Bayesian experimental design, and apply them to the problem of inferring the dynamical parameters of a quantum system. We design the algorithm with practicality in mind by including parameters that control trade-offs between the requirements on computational and experimental resources. The algorithm can be implemented online (during experimental data collection), avoiding the need for storage and post-processing. Most importantly, our algorithm is capable of learning Hamiltonian parameters even when the parameters change from experiment-to-experiment, and also when additional noise processes are present and unknown. The algorithm also numerically estimates the Cramer-Rao lower bound, certifying its own performance.Comment: 24 pages, 12 figures; to appear in New Journal of Physic

Transition from an M1 to a Mixed Neuroinflammatory Phenotype Increases Amyloid Deposition in APP/PS1 Transgenic Mice

BACKGROUND: The polarization to different neuroinflammatory phenotypes has been described in early Alzheimer\u27s disease, yet the impact of these phenotypes on amyloid-beta (Aβ) pathology remains unknown. Short-term studies show that induction of an M1 neuroinflammatory phenotype reduces Aβ, but long-term studies have not been performed that track the neuroinflammatory phenotype. METHODS: Wild-type and APP/PS1 transgenic mice aged 3 to 4 months received a bilateral intracranial injection of adeno-associated viral (AAV) vectors expressing IFNγ or green fluorescent protein in the frontal cortex and hippocampus. Mice were sacrificed 4 or 6 months post-injection. ELISA measurements were used for IFNγ protein levels and biochemical levels of Aβ. The neuroinflammatory phenotype was determined through quantitative PCR. Microglia, astrocytes, and Aβ levels were assessed with immunohistochemistry. RESULTS: AAV expressing IFNγ induced an M1 neuroinflammatory phenotype at 4 months and a mixed phenotype along with an increase in Aβ at 6 months. Microglial staining was increased at 6 months and astrocyte staining was decreased at 4 and 6 months in mice receiving AAV expressing IFNγ. CONCLUSIONS: Expression of IFNγ through AAV successfully induced an M1 phenotype at 4 months that transitioned to a mixed phenotype by 6 months. This transition also appeared with an increase in amyloid burden suggesting that a mixed phenotype, or enhanced expression of M2a and M2c markers, could contribute to increasing amyloid burden and disease progression

VAX/LSI-11/CAMAC Nuclear Data Acquisition System under Development at the W.K. Kellogg Radiation Laboratory, Caltech

A CAMAC data acquisition system is currently under development at the W.K. Kellogg Radiation Laboratory which utilizes LSI-11 crate controllers and a 250 Kbyte/sec 7-computer Q-bus DMA network. The central network computer is a VAX 11/750 with Unibus and Q-bus adaptors. Processing is distributed between the LSI-11s and the VAX as required to meet input-output and event processing speeds needed by the experiment. Use of the Q-bus on all machines allows CAMAC controllers and tape drives to be moved as needed between the LSI-11s and the VAX