3,457 research outputs found
Testing LSND at long-baseline neutrino experiments
Recently it was suggested that two very different mass-squared differences
play a role in atmospheric neutrino oscillations. The larger of these also
accounts for the LSND result and the smaller of these also drives the solar
neutrino oscillations. We consider the predictions of this scheme for
long-baseline experiments. We find that high statistics experiments, such as
MINOS, can observe a clean signal for this scheme, which is clearly
distinguishable from the usual scheme of atmospheric neutrino oscillations
driven by a single mass-squared difference.Comment: 13 pages, 3 figure
The Role of Consciousness in Memory
Conscious events interact with memory systems in learning, rehearsal and retrieval (Ebbinghaus 1885/1964; Tulving 1985). Here we present hypotheses that arise from the IDA computional model (Franklin, Kelemen and McCauley 1998; Franklin 2001b) of global workspace theory (Baars 1988, 2002). Our primary tool for this exploration is a flexible cognitive cycle employed by the IDA computational model and hypothesized to be a basic element of human cognitive processing. Since cognitive cycles are hypothesized to occur five to ten times a second and include interaction between conscious contents and several of the memory systems, they provide the means for an exceptionally fine-grained analysis of various cognitive tasks. We apply this tool to the small effect size of subliminal learning compared to supraliminal learning, to process dissociation, to implicit learning, to recognition vs. recall, and to the availability heuristic in recall. The IDA model elucidates the role of consciousness in the updating of perceptual memory, transient episodic memory, and procedural memory. In most cases, memory is hypothesized to interact with conscious events for its normal functioning. The methodology of the paper is unusual in that the hypotheses and explanations presented are derived from an empirically based, but broad and qualitative computational model of human cognition
Preventive Effects of Resveratrol against Beta Adrenergic Catecholamine-Induced Acute Myocardial Stress during Experimental Hyperglycemia in in Vivo and in Vitro Models
Aim: To evaluate the cardioprotective effects of resveratrol during hyperglycemic conditions in in vitro and in vivo models. Study Design: H9c2 cardiomyocyte cells were used as in vitro models and adult male Wistar strain albino rats were used as in vivo models. Activities of LDH and levels of lipid peroxides, total reduced glutathione were the end point indicators for the in vitro studies.For the in vivo studies the activities of membrane bound ATPases, levels of lipid peroxides, enzymic and non enzymic antioxidants were the end point indicators. Place and Duration of Study: The study was conducted at the Department of Microbiology and Biotechnology, Bangalore University, Bangalore, between January 2014 and June 2014. Methodology: To mimic myocardial injury during diabetic conditions (in vitro), the H9c2 cells were maintained in high glucose environment followed by isoproterenol challenge. For in vivo studies the animals were segregated as follows: Untreated control; Myocardial stress induced animals (Isoproterenol 150 mg/kg body wt i.p); Diabetic rats (Streptozotocin, 50 mg/kg body wt,i.p);Myocardial stress induced diabetic rats; resveratrol per se (5 mg/kg.body wt. orally for 21 days), and resveratrol pretreated prior to induction of diabetes and myocardial stress. Results: H9c2 cells given glucose insult and challenged with isoproterenol showed severe cytotoxicity and stress as elicited by increased LDH release, increased lipid peroxides and depleted GSH levels. These changes were prevented in the cells pretreated with resveratrol prior to isoproterenol/glucose challenge. The diabetic rats induced with myocardial stress showed significant alterations in the activity of membrane bound phosphatases, levels of lipid peroxides, enzymic and non enzymic antioxidants. Pre-treatment with resveratrol prevented these alterations thereby implicating cardioprotective effects during hyperglycemic conditions Conclusion: Resveratrol could combat myocardial stress during experimental hyperglycemia in in vitro and in vivo model
A study on stability analysis of atrial repolarization variability using ARX model in sinus rhythm and atrial tachycardia ECGs
© 2016 Elsevier Ireland Ltd Background The interaction between the PTa and PP interval dynamics from the surface ECG is seldom explained. Mathematical modeling of these intervals is of interest in finding the relationship between the heart rate and repolarization variability. Objective The goal of this paper is to assess the bounded input bounded output (BIBO) stability in PTa interval (PTaI) dynamics using autoregressive exogenous (ARX) model and to investigate the reason for causing instability in the atrial repolarization process. Methods Twenty-five male subjects in normal sinus rhythm (NSR) and ten male subjects experiencing atrial tachycardia (AT) were included in this study. Five minute long, modified limb lead (MLL) ECGs were recorded with an EDAN SE-1010 PC ECG system. The number of minute ECGs with unstable segments (N us ) and the frequency of premature activation (PA) (i.e. atrial activation) were counted for each ECG recording and compared between AT and NSR subjects. Results The instability in PTaI dynamics was quantified by measuring the numbers of unstable segments in ECG data for each subject. The unstable segments in the PTaI dynamics were associated with the frequency of PA. The presence of PA is not the only factor causing the instability in PTaI dynamics in NSR subjects, and it is found that the cause of instability is mainly due to the heart rate variability (HRV). C onclusion The ARX model showed better prediction of PTa interval dynamics in both groups. The frequency of PA is significantly higher in AT patients than NSR subjects. A more complex model is needed to better identify and characterize healthy heart dynamics
Local Invariants and Pairwise Entanglement in Symmetric Multi-qubit System
Pairwise entanglement properties of a symmetric multi-qubit system are
analyzed through a complete set of two-qubit local invariants. Collective
features of entanglement, such as spin squeezing, are expressed in terms of
invariants and a classifcation scheme for pairwise entanglement is proposed.
The invariant criteria given here are shown to be related to the recently
proposed (Phys. Rev. Lett. 95, 120502 (2005)) generalized spin squeezing
inequalities for pairwise entanglement in symmetric multi-qubit states.Comment: 9 pages, 2 figures, REVTEX, Replaced with a published versio
Using Functional Near Infrared Spectroscopy (fNIRS) to study dynamic stereoscopic depth perception
The parietal cortex has been widely implicated in the processing of depth perception by many neuroimaging studies, yet functional near infrared spectroscopy (fNIRS) has been an under-utilised tool to examine the relationship of oxy- ([HbO]) and de-oxyhaemoglobin ([HbR]) in perception. Here we examine the haemodynamic response (HDR) to the processing of induced depth stimulation using dynamic random-dot-stereograms (RDS). We used fNIRS to measure the HDR associated with depth perception in healthy young adults (n = 13, mean age 24). Using a blocked design, absolute values of [HbO] and [HbR] were recorded across parieto-occipital and occipital cortices, in response to dynamic RDS. Control and test images were identical except for the horizontal shift in pixels in the RDS that resulted in binocular disparity and induced the percept of a 3D sine wave that 'popped out' of the test stimulus. The control stimulus had zero disparity and induced a 'flat' percept. All participants had stereoacuity within normal clinical limits and successfully perceived the depth in the dynamic RDS. Results showed a significant effect of this complex visual stimulation in the right parieto-occipital cortex (p < 0.01, η(2) = 0.54). The test stimulus elicited a significant increase in [HbO] during depth perception compared to the control image (p < 0.001, 99.99 % CI [0.008-0.294]). The similarity between the two stimuli may have resulted in the HDR of the occipital cortex showing no significant increase or decrease of cerebral oxygenation levels during depth stimulation. Cerebral oxygenation measures of [HbO] confirmed the strong association of the right parieto-occipital cortex with processing depth perception. Our study demonstrates the validity of fNIRS to investigate [HbO] and [HbR] during high-level visual processing of complex stimuli
Debris Disks in the Scorpius-Centaurus OB Association Resolved by ALMA
We present a CO(2-1) and 1240 um continuum survey of 23 debris disks with
spectral types B9-G1, observed at an angular resolution of 0.5-1 arcsec with
the Atacama Large Millimeter/Submillimeter Array (ALMA). The sample was
selected for large infrared excess and age ~10 Myr, to characterize the
prevalence of molecular gas emission in young debris disks. We identify three
CO-rich debris disks, plus two additional tentative (3-sigma) CO detections.
Twenty disks were detected in the continuum at the >3-sigma level. For the 12
disks in the sample that are spatially resolved by our observations, we perform
an independent analysis of the interferometric continuum visibilities to
constrain the basic dust disk geometry, as well as a simultaneous analysis of
the visibilities and broad-band spectral energy distribution to constrain the
characteristic grain size and disk mass. The gas-rich debris disks exhibit
preferentially larger outer radii in their dust disks, and a higher prevalence
of characteristic grain sizes smaller than the blowout size. The gas-rich disks
do not exhibit preferentially larger dust masses, contrary to expectations for
a scenario in which a higher cometary destruction rate would be expected to
result in a larger mass of both CO and dust. The three debris disks in our
sample with strong CO detections are all around A stars: the conditions in
disks around intermediate-mass stars appear to be the most conducive to the
survival or formation of CO.Comment: 16 pages, 6 figures, accepted for publication in Ap
India rice export and virtual water trade
The present study aimed to assess water footprint in the production and export of rice in India. From recent few years, the water footprint conception in full swing to inward detection around the world. The amplified attention in the water footprint has impelled the trade of commodities between countries. Water footprint in the rice field is a sign of water use that exhibits direct and indirect water usage in the rice field. Rice is an important food crop in India. It accesses the flows of water virtually between countries/regions of the world to illustrate the dependency of countries/regions on water resources with other countries/regions under diverse feasible futures. Hence, it is gaining consequence to calculate the water foot print in production as well as export of rice. The Indian rice production and export of rice was calculated by using international trade and domestic production data. The study results indicated that the global footprint of rice production was 235774 Mm3 per ton which was 53 % of green water footprint, 41 % of blue water footprint and 6 % of grey water footprint for 2018-19. The virtual water flowed in trade was 24354 Mm3/year and the percolation was 16924 Mm3/year since rice is a more water consuming crop. The share of basmati and non-basmati trade accounted was 16 % and 42 %, respectively. Virtual water trade in rice can be minimized by exporting less water demand and high-value crops, proper water harvesting structures and other agronomic practices
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