164 research outputs found
Some aspects of performance at a psychokinetic task
Psychokinetic phenomena are currently anomalous with respect to physics. They are not generally accepted as genuine nor are their possible physical mechanisms understood. It is argued here that a certain class of psychokinetic phenomena, termed "directly detectable" psychokinetic effects, are likely to yield possibly important insights into the physical mechanisms mediating psychokinetic phenomena generally. The current use within parapsychological research of randomly behaving psychokinetic target systems is criticised on several grounds. They are of limited scope for use in delineation of physical mechanisms involved in psychokinesis, and their intrinsic characteristics prevent subjects from utilising their possible capacity to learn to produce larger magnitude effects. It is argued that instrumented directly detectable psychokinetic tasks have characteristics which may allow subjects to treat their psychokinetic ability as akin to a normal skill which can be improved with continued practice, using an experimental paradigm similar to that used in the biofeedback training of physiological functions. The task used in this work was a microscopic form of psychokinetic metal-bending, whereby subjects produce pulse-like electrical outputs in a ceramic piezoelectric element used as psychokinetic target. Subjects were not allowed to touch the target and many effects were obtained under witnessed conditions with subjects situated several metres from it. One pilot and three principal longitudinal training studies were performed with a total of seventeen subjects. Six of the seventeen subjects showed significant improvement in their psychokinetic performance in the training studies, one showed a non-significant increase. The other ten failed to show any convincing signs of psychokinetic output. Three of the successful subjects did not show convincing signs of voluntary control over their effects, three did. Large individual differences were found including different rates of learning and levels of initial and final ability. This research was performed by Julian David Isaacs in preparation for the degree of Doctor of Philosophy and was submitted in 1984
A Double Blind Study of the "Biocircuit", a Putative Subtle-Energy-Based Relaxation Device
Biocircuits are passive devices which are reported to cause relaxation in users, supposedly by facilitation of bodily subtle energy flow. A repeated-measures, within-subjects control, doubleblind study was performed to test whether a "relaxation" biocircuit would produce more relaxation than a placebo-control biocircuit. The study design controlled for expectation, order first-time effects and ultradian rhythms. Dependent measures included four physiological variables relating to arousal and relaxation (frontalis muscle tension, one monopolar channel of EEG monitored for theta episodes, finger temperature, finger skin conductance) and a tenitem comparative questionnaire used to rank subjective experiences relating to relaxation in session. Twelve subjects completed four sessions each. The first session for all subjects was used only for familiarization and its data were not analyzed. Subjects then completed three more sessions each, treatment order being counterbalanced and randomly assigned across subjects. The three sessions exposed subjects to a "relaxation" biocircuit, a placebo-control "dummy" biocircuit and a "tension" biocircuit. The EEG theta measure showed significantly more theta episodes associated with the relaxation device than with the placebo control (Wilcoxon signed ranks test: p .025 one-tailed). The frontalis muscle tension measure showed significantly lower tension levels associated with the relaxation device than with the placebo control (Wilcoxon signed ranks test: p .01 one tailed). The skin conductivity and temperature measures did not reach significance in any direction across any pair of treatments. Five of the ten questionnaire items comparing the relaxation device with the placebo-control significantly favored the relaxation device (all by Sign test with a priori probability of .5): subjective estimate of relaxation (p .0002), sensations of warmth (p .03), non-ordinariness of experience (p .02), perceived effectiveness (p .02), perceived benefit (p S; .02). No questionnaire items at the .05 significance level favored the placebo control over the relaxation device. The findings of the study demonstrate the superiority of the relaxation biocircuit over a placebo control for producing relaxation under fully controlled double-blind conditions. KEYWORDS: "Biocircuit," psychophysiology, brainwaves, experiential, relaxation, physiology, placebo, polarit
Tracking evaporative cooling of a mesoscopic atomic quantum gas in real time
The fluctuations in thermodynamic and transport properties in many-body
systems gain importance as the number of constituent particles is reduced.
Ultracold atomic gases provide a clean setting for the study of mesoscopic
systems; however, the detection of temporal fluctuations is hindered by the
typically destructive detection, precluding repeated precise measurements on
the same sample. Here, we overcome this hindrance by utilizing the enhanced
light--matter coupling in an optical cavity to perform a minimally invasive
continuous measurement and track the time evolution of the atom number in a
quasi two-dimensional atomic gas during evaporation from a tilted trapping
potential. We demonstrate sufficient measurement precision to detect atom
number fluctuations well below the level set by Poissonian statistics.
Furthermore, we characterize the non-linearity of the evaporation process and
the inherent fluctuations of the transport of atoms out of the trapping volume
through two-time correlations of the atom number. Our results establish coupled
atom--cavity systems as a novel testbed for observing thermodynamics and
transport phenomena in mesosopic cold atomic gases and, generally, pave the way
for measuring multi-time correlation functions of ultracold quantum gases.Comment: Significantly extended discussion of Fig. 4. Accepted for publication
in Phys. Rev.
Autonomous feedback stabilization of a cavity-coupled spin oscillator
We report out-of-equilibrium stabilization of the collective spin of an
atomic ensemble through autonomous feedback by an optical cavity. For a
magnetic field applied at an angle to the cavity axis, dispersive coupling to
the cavity provides sensitivity to a combination of the longitudinal and
transverse spin. Coherent backaction from this measurement, conditioned by the
optical cavity susceptibility, stabilizes the collective spin state at an
arbitrary energy. The set point tracking and closed-loop gain spectrum of the
feedback system are characterized and found to agree closely with analytic
predictions
Case Study of Ecstatic Meditation: fMRI and EEG Evidence of Self-Stimulating a Reward System
We report the first neural recording during ecstatic meditations called jhanas and test whether a brain reward system plays a role in the joy reported. Jhanas are Altered States of Consciousness (ASC) that imply major brain changes based on subjective reports: (1) external awareness dims, (2) internal verbalizations fade, (3) the sense of personal boundaries is altered, (4) attention is highly focused on the object of meditation, and (5) joy increases to high levels. The fMRI and EEG results from an experienced meditator show changes in brain activity in 11 regions shown to be associated with the subjective reports, and these changes occur promptly after jhana is entered. In particular, the extreme joy is associated not only with activation of cortical processes but also with activation of the nucleus accumbens (NAc) in the dopamine/opioid reward system. We test three mechanisms by which the subject might stimulate his own reward system by external means and reject all three. Taken together, these results demonstrate an apparently novel method of self-stimulating a brain reward system using only internal mental processes in a highly trained subject
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Highly selective and solvent-dependent reduction of Nitrobenzene to N-phenylhydroxylamine, azoxybenzene, and aniline catalyzed by phosphino-modified polymer immobilized ionic liquid-stabilized AuNPs
Gold nanoparticles stabilized by phosphine-decorated polymer immobilized ionic liquids (AuNP@PPh2-PIILP) is an extremely efficient multiproduct selective catalyst for the sodium borohydride-mediated reduction of nitrobenzene giving N-phenylhydroxylamine, azoxybenzene, or aniline as the sole product under mild conditions and a very low catalyst loading. The use of a single nanoparticle-based catalyst for the partial and complete reduction of nitroarenes to afford three different products with exceptionally high selectivities is unprecedented. Under optimum conditions, thermodynamically unfavorable N-phenylhydroxylamine can be obtained as the sole product in near quantitative yield in water, whereas a change in reaction solvent to ethanol results in a dramatic switch in selectivity to afford azoxybenzene. The key to obtaining such a high selectivity for N-phenylhydroxylamine is the use of a nitrogen atmosphere at room temperature as reactions conducted under an inert atmosphere occur via the direct pathway and are essentially irreversible, while reactions in air afford significant amounts of azoxy-based products by virtue of competing condensation due to reversible formation of N-phenylhydroxylamine. Ultimately, aniline can also be obtained quantitatively and selectively by adjusting the reaction temperature and time accordingly. Introduction of PEG onto the polyionic liquid resulted in a dramatic improvement in catalyst efficiency such that N-phenylhydroxylamine could be obtained with a turnover number (TON) of 100 000 (turnover frequency (TOF) of 73 000 h–1, with >99% selectivity), azoxybenzene with a TON of 55 000 (TOF of 37 000 h–1 with 100% selectivity), and aniline with a TON of 500 000 (TOF of 62 500 h–1, with 100% selectivity). As the combination of ionic liquid and phosphine is required to achieve high activity and selectivity, further studies are currently underway to explore whether interfacial electronic effects influence adsorption and thereby selectivity and whether channeling of the substrate by the electrostatic potential around the AuNPs is responsible for the high activity. This is the first report of a AuNP-based system that can selectively reduce nitroarenes to either of two synthetically important intermediates as well as aniline and, in this regard, is an exciting discovery that will form the basis to develop a continuous flow process enabling facile scale-up
Settling for second best: when should doctors agree to parental demands for suboptimal medical treatment?
Background Doctors sometimes encounter parents who object to prescribed treatment for their children, and request suboptimal substitutes be administered instead (suboptimal being defined as less effective and/or more expensive). Previous studies have focused on parental refusal of treatment and when this should be permitted, but the ethics of requests for suboptimal treatment has not been explored.
Methods The paper consists of two parts: an empirical analysis and an ethical analysis. We performed an online survey with a sample of the general public to assess respondents’ thresholds for acceptable harm and expense resulting from parental choice, and the role that religion played in their judgement. We also identified and applied existing ethical frameworks to the case described in the survey to compare theoretical and empirical results.
Results Two hundred and forty-two Mechanical Turk workers took our survey and there were 178 valid responses (73.6%). Respondents’ agreement to provide treatment decreased as the risk or cost of the requested substitute increased (p<0.001). More than 50% of participants were prepared to provide treatment that would involve a small absolute increased risk of death for the child (<5%) and a cost increase of US$<500, respectively. Religiously motivated requests were significantly more likely to be allowed (p<0.001). Existing ethical frameworks largely yielded ambiguous results for the case. There were clear inconsistencies between the theoretical and empirical results.
Conclusion Drawing on both survey results and ethical analysis, we propose a potential model and thresholds for deciding about the permissibility of suboptimal treatment requests
Evaluation of polygenic risk scores for breast and ovarian cancer risk prediction in BRCA1 and BRCA2 mutation carriers
Background: Genome-wide association studies (GWAS) have identified 94 common single-nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk and 18 associated with ovarian cancer (OC) risk. Several of these are also associated with risk of BC or OC for women who carry a pathogenic mutation in the high-risk BC and OC genes BRCA1 or BRCA2. The combined effects of these variants on BC or OC risk for BRCA1 and BRCA2 mutation carriers have not yet been assessed while their clinical management could benefit from improved personalized risk estimates.
Methods: We constructed polygenic risk scores (PRS) using BC and OC susceptibility SNPs identified through population-based GWAS: for BC (overall, estrogen receptor [ER]-positive, and ER-negative) and for OC. Using data from 15 252 female BRCA1 and 8211 BRCA2 carriers, the association of each PRS with BC or OC risk was evaluated using a weighted cohort approach, with time to diagnosis as the outcome and estimation of the hazard ratios (HRs) per standard deviation increase in the PRS.
Results: The PRS for ER-negative BC displayed the strongest association with BC risk in BRCA1 carriers (HR = 1.27, 95% confidence interval [CI] = 1.23 to 1.31, P = 8.2 x 10(53)). In BRCA2 carriers, the strongest association with BC risk was seen for the overall BC PRS (HR = 1.22, 95% CI = 1.17 to 1.28, P = 7.2 x 10(-20)). The OC PRS was strongly associated with OC risk for both BRCA1 and BRCA2 carriers. These translate to differences in absolute risks (more than 10% in each case) between the top and bottom deciles of the PRS distribution; for example, the OC risk was 6% by age 80 years for BRCA2 carriers at the 10th percentile of the OC PRS compared with 19% risk for those at the 90th percentile of PRS.
Conclusions: BC and OC PRS are predictive of cancer risk in BRCA1 and BRCA2 carriers. Incorporation of the PRS into risk prediction models has promise to better inform decisions on cancer risk management
The Fourth International Symposium on the Intraductal Approach to Breast Cancer, Santa Barbara, California, 10–13 March 2005
Intraductal approaches encompass procedures and technologies that are designed to access and interrogate the ductal–alveolar systems of the human breast, and include nipple aspiration, ductal lavage, random periareolar fine needle aspiration, and ductoscopy. These approaches are being used to collect and analyze fluids and cells to develop methods for breast cancer detection and risk assessment; to introduce imaging technologies to explore the mammary tree for abnormalities; to administer therapeutic and/or preventive agents directly to the breast tissue; and to explore the biology of the normal mammary gland. The latest research findings in these areas, presented at The 4th International Symposium on the Intraductal Approach to Breast Cancer in 2005, are summarized in this report
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