901 research outputs found
Relativistic nuclear structure effects in quasielastic neutrino scattering
Charged-current cross sections are calculated for quasielastic neutrino and
antineutrino scattering using a relativistic meson-nucleon model. We examine
how nuclear-structure effects, such as relativistic random-phase-approximation
(RPA) corrections and momentum-dependent nucleon self-energies, influence the
extraction of the axial form factor of the nucleon. RPA corrections are
important only at low-momentum transfers. In contrast, the momentum dependence
of the relativistic self-energies changes appreciably the value of the
axial-mass parameter, , extracted from dipole fits to the axial form
factor. Using Brookhaven's experimental neutrino spectrum we estimate the
sensitivity of M to various relativistic nuclear-structure effects.Comment: 26 pages, revtex, 6 postscript figures (available upon request
Physical properties of charred pellets after two months of storage
Six types of charred pellets: canola straw, willow, bagasse, wheat straw, switchgrass and miscanthus, were stored for a period of two months at room temperature 25±2 °C in sealed containers. The tests were part of off gassing experiment on charred and uncharred pellets. The following physical properties of the pellets were measured: bulk density, individual pellet density, Individual pellet dimensions were similar between samples but the pellet mass ranged from 0.79 g for switchgrass to 1.13 g for bagasse pellet.
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Dopamine depletion effects on cognitive flexibility as modulated by tDCS of the dlPFC
Background
Recent evidence suggests that transcranial direct current stimulation (tDCS) may interact with the dopaminergic system to affect cognitive flexibility.
Objective/hypotheses: We examined whether putative reduction of dopamine levels through the acute phenylalanine/tyrosine depletion (APTD) procedure and excitatory anodal tDCS of the dorsolateral prefrontal cortex (dlPFC) are causally related to cognitive flexibility as measured by task switching and reversal learning.
Method
A double-blind, sham-controlled, randomised trial was conducted to test the effects of combining anodal tDCS and depletion of catecholaminergic precursor tyrosine on cognitive flexibility.
Results
Anodal tDCS and tyrosine depletion had a significant effect on task switching, but not reversal learning. Whilst perseverative errors were significantly improved by anodal tDCS, the APTD impaired reaction times. Importantly, the combination of APTD and anodal tDCS resulted in cognitive performance which did not statistically differ to that of the control condition.
Conclusions
Our results suggest that the effects of tDCS on cognitive flexibility are modulated by dopaminergic tone
Ginseng and Ginkgo Biloba effects on cognition as modulated by cardiovascular reactivity: A randomised trial
Background
There is some evidence to suggest that ginseng and Ginkgo biloba can improve cognitive performance, however, very little is known about the mechanisms associated with such improvement. Here, we tested whether cardiovascular reactivity to a task is associated with cognitive improvement.
Methodology/Principal findings
Using a double-blind, placebo controlled, crossover design, participants (N = 24) received two doses of Panax Ginseng (500, 1000 mg) or Ginkgo Biloba (120, 240 mg) (N = 24), and underwent a series of cognitive tests while systolic, diastolic, and heart rate readings were taken. Ginkgo Biloba improved aspects of executive functioning (Stroop and Berg tasks) in females but not in males. Ginseng had no effect on cognition. Ginkgo biloba in females reversed the initial (i.e. placebo) increase in cardiovascular reactivity (systolic and diastolic readings increased compared to baseline) to cognitive tasks. This effect (reversal) was most notable after those tasks (Stroop and Iowa) that elicited the greatest cardiovascular reactivity during placebo. In males, although ginkgo also decreased cardiovascular readings, it did so from an initial (placebo) blunted response (i.e. decrease or no change from baseline) to cognitive tasks. Ginseng, on the contrary, increased cardiovascular readings compared to placebo.
Conclusions/Significance
These results suggest that cardiovascular reactivity may be a mechanism by which ginkgo but not ginseng, in females is associated with certain forms of cognitive improvement
Characterizing early adolescent food waste using the mobile food record.
This study aimed to assess the amount of plate waste and how plate waste
was disposed by early adolescent girls using a mobile food record
(mFR). Participants were girls nine to thirteen years residing in O’ahu,
Hawai’i (n = 93). Foods selected and leftover were estimated
using a three day mFR. Each leftover food was then classified as thrown
into the trash, fed to a pet, eaten later, or other (e.g., composted).
Repeated measures analyses of variance (ANOVA) were conducted and
Tukey’s post-hoc test were used to adjust for multiple comparisons
between times (breakfast, lunch, dinner, and snack) on leftover food and
leftover food thrown into the trash. The percentage of food leftover
and thrown into the trash was highest at lunch. The percentage of
protein, grain, vegetables, fruit, and dairy leftover at lunch were
unexpectedly low compared to previous studies. The median for percentage
of food thrown into the trash at lunch was <5% for all food groups,
and was consistently low across the day (<10%). Average energy intake
was 436 kcal (±216) at lunch, and 80% of caregivers reported total
household income as ≥$70,000. Studies in real-time using technology over
full days may better quantify plate waste among adolescents
Multimodal fusion : gesture and speech input in augmented reality environment
Augmented Reality (AR) has the capability to interact with the virtual objects and physical objects simultaneously since it combines the real world with virtual world seamlessly. However, most AR interface applies conventional Virtual Reality (VR) interaction techniques without modification. In this paper we explore the multimodal fusion for AR with speech and hand gesture input. Multimodal fusion enables users to interact with computers through various input modalities like speech, gesture, and eye gaze. At the first stage to propose the multimodal interaction, the input modalities are decided to be selected before be integrated in an interface. The paper presents several related works about to recap the multimodal approaches until it recently has been one of the research trends in AR. It presents the assorted existing works in multimodal for VR and AR. In AR, multimodal considers as the solution to improve the interaction between the virtual and physical entities. It is an ideal interaction technique for AR applications since AR supports interactions in real and virtual worlds in the real-time. This paper describes the recent studies in AR developments that appeal gesture and speech inputs. It looks into multimodal fusion and its developments, followed by the conclusion.This paper will give a guideline on multimodal fusion on how to integrate the gesture and speech inputs in AR environment
Carcinogenesis in Prostate Cancer: The role of Long Non-Coding RNAs
LncRNAs appear to play a considerable role in tumourigenesis through regulating key processes in cancer cells such as proliferative signalling, replicative immortality, invasion and metastasis, evasion of growth suppressors, induction of angiogenesis and resistance to apoptosis. LncRNAs have been reported to play a role in prostate cancer, particularly in regulating the androgen receptor signalling pathway. In this review article, we summarise the role of 34 lncRNAs in prostate cancer with a particular focus on their role in the androgen receptor signalling pathway and the epithelial to mesenchymal transition pathway
Medium Modification to the -Meson Mass in the Walecka Model
We calculate the effective mass of the meson in nuclear matter in a
relativistic random-phase approximation to the Walecka model. The dressing of
the meson propagator is driven by its coupling to particle-hole pairs and
nucleon-antinucleon () excitations. We report a reduction in the
-meson mass of about 170~MeV at nuclear-matter saturation density. This
reduction arises from a competition between the density-dependent
(particle-hole) dressing of the propagator and vacuum polarization (
pairs). While density-dependent effects lead to an increase in the mass
proportional to the classical plasma frequency, vacuum polarization leads to an
even larger reduction caused by the reduced effective nucleon mass in the
medium.Comment: 14 pages in ReVTeX, 3 uuencoded figures are available upon request,
FSU-SCRI-93-132 and ADP-93-223/T14
Cratoxylum glaucum and cratoxylum arborescens (Guttiferae)-two potential source of antioxidant agents.
Our detailed chemical studies on Cratoxylum glaucum and C. arborescens have revealed the presence of 5-demethoxycadensin G (1), fuscaxanthone C (2), b-mangostin (3), 3-geranyloxy-6-methyl-1,8-dihydroxyanthraquinone (4), vismiaquinone (5), 1,8-dihydroxy-3-methoxy-6-methylanthraquinone (6), stigmasterol (7) and friedelin (8). Structural elucidations of these compounds were achieved by using 1D and 2D NMR spectroscopic experiments. Antioxidant tests conducted on these two plant species gave promising results with both species indicating good antioxidant inhibiting properties. This is a first report on 5-demethoxycadensin G (1) and b-mangostin (3) from Cratoxylum glaucum as well as the antioxidant properties of these two species
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