522 research outputs found
Spin-Parity Analysis of the Centrally produced KsKs system at 800 GeV
Results are presented of the spin-parity analysis on a sample of centrally
produced mesons in the reaction (p p -> p_{slow} K_s K_s p_{fast}) with 800 GeV
protons on liquid hydrogen. The spin-parity analysis in the mass region between
threshold and 1.58 GeV/c^2 shows that the (K_s K_s) system is produced mainly
in S-wave. The f_0(1500) is clearly observed in this region. Above 1.58 GeV/c^2
two solutions are possible, one with mainly S-wave and another with mainly
D-wave. This ambiguity prevents a unique determination of the spin of the
f_J(1710) meson.Comment: 6 pages, including 6 figures. LaTex, uses 'espcrc2.sty'. To appear in
LEAP'96 proceeding
GC-MS determination of organochlorine pesticides in medicinal plants harvested in Brazil
A method using Gas Chromatography coupled to Mass Spectrometry (GC-MS) for the determination of hexachlorobenzene, lindane, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, 4,4'-DDT and 4,4'-DDE in leaves of Mikania laevigata, Maytenus ilicifolia and Cordia verbenacea was developed. Extraction of the pesticides was carried out by solid-liquid extraction (SLE), followed by clean-up in solid phase mixed cartridge (Florisil and silica-gel). Quantification was performed using GC-MS in the selected ion monitoring mode. Mean recovery rates of 70 to 124% were obtained. The inter-assay precision of a sample fortified with 200 ng g-1 of each pesticide was in the range of 1.0 to 7.3%. The quantitation limits ranged from 3.0 to 30 ng g-1 and were below the Maximum Residue Limit (MRL) for all the pesticides under study. The method was employed to analyze samples of Mikania laevigata, Maytenus ilicifolia and Cordia verbenacea from an experimental field in Paulínia, SP, Brazil. The samples presented contamination with dieldrin above the MRL established by the European Pharmacopoeia (50 ng g-1)
Validity and invariance of measurement of the satisfaction with love life scale in older adults
In recent years, interest in satisfaction with love life (SWLL) has increased. Empirical evidence demonstrated that SWLL favors subjective well-being, physical and mental health, marital quality and stability. In this regard, the study aimed to examine evidence based on the internal structure validity, reliability, and measurement invariance of the Peruvian version of the Satisfaction with Love Life Scale (SWLLS). The participants were 323 older adults recruited from the region of San Martin (Peru) with an average age of 68.73 years (SD = 7.17). The sample comprised of 49.5% women and 50.5% men. The results supported the one-dimensional model and adequate reliability of the SWLLS. A multi-group analysis provided evidence of configural, metric, and scale invariance across genders. The findings verified the validity and reliability of the Peruvian version of the SWLLS, which can be used to measure SWLL.Universidad del Nort
Affinity proteomics reveals elevated muscle proteins in plasma of children with cerebral malaria
Systemic inflammation and sequestration of parasitized erythrocytes are central processes in the pathophysiology of severe Plasmodium falciparum childhood malaria. However, it is still not understood why some children are more at risks to develop malaria complications than others. To identify human proteins in plasma related to childhood malaria syndromes, multiplex antibody suspension bead arrays were employed. Out of the 1,015 proteins analyzed in plasma from more than 700 children, 41 differed between malaria infected children and community controls, whereas 13 discriminated uncomplicated malaria from severe malaria syndromes. Markers of oxidative stress were found related to severe malaria anemia while markers of endothelial activation, platelet adhesion and muscular damage were identified in relation to children with cerebral malaria. These findings suggest the presence of generalized vascular inflammation, vascular wall modulations, activation of endothelium and unbalanced glucose metabolism in severe malaria. The increased levels of specific muscle proteins in plasma implicate potential muscle damage and microvasculature lesions during the course of cerebral malaria
Dry matter accumulation and carbohydrate composition of a new cultivar of maize, "Sugary-Opaque-2-Waxy".
O acúmulo de matéria seca e a composição de carboidratos de uma nova cultivar de milho, o triplo mutante Sugary-Opaque-2-Waxy, foram estudados comparativamente em relação às cultivares Sugary-Opaque-2, Waxy-Sugary-Opaque-2 e uma cultivar de milho (Zea mays L.) normal. De uma maneira geral, todas as cvs. estudadas apresentaram, aos 25 dias após a polinização (DAP) teores semelhantes de açúcares solúveis redutores. As cultivares que continham o gene sugary apresentaram teores mais elevados de acúcares solúveis totais e de fitoglicogênio, em comparação com as cultivares com endospernia amiláceo. Uma relação inversa foi observada para o conteúdo de amido. A avaliação do acúmulo de matéria seca, em diferentes estádios de maturação, 15, 20, 25, 30 e 35 DAP, indicou que o milho normal e o triplo mutante apresentaram os maiores e menores valores de porcentagem de peso seco, respectivamente. O triplo mutante mostrou acúmulo de matéria seca mais lento do que seus ascendentes, proporcionando um período mais prolongado de colheita como milho verde, favorecendo o seu consumo in naturaDry matter accumulation and carbohydrate composition of a new cultivar of maize (Zea mays L.), te triple mutant Sugary-Opaque-2-Waxy, was comparatively studied in relation to the cultivars Sugary, Opaque-2, Waxy,Sugary-Opaque-2 and Maya Normal in general, all cultivars showed similar content of soluble reducing sugars. The cultivars with te sugary gene showed higher content of total soluble sugars and phytoglycogen than those with the starchy endosperm. The opposite was found to te starch content Maya Normal and te triple mutant showed, respectively, te higher and lower values for dry matter accumulation at the different stages of endosperm development (15, 20, 25, 30 and 35 days after poilination - DAP). The lower rate of dry matter accumulation suggests that te triple mutant would be more appropriate to be consumed as sweet corn
Yang-Mills instantons and dyons on homogeneous G_2-manifolds
We consider Lie G-valued Yang-Mills fields on the space R x G/H, where G/H is
a compact nearly K"ahler six-dimensional homogeneous space, and the manifold R
x G/H carries a G_2-structure. After imposing a general G-invariance condition,
Yang-Mills theory with torsion on R x G/H is reduced to Newtonian mechanics of
a particle moving in R^6, R^4 or R^2 under the influence of an inverted
double-well-type potential for the cases G/H = SU(3)/U(1)xU(1),
Sp(2)/Sp(1)xU(1) or G_2/SU(3), respectively. We analyze all critical points and
present analytical and numerical kink- and bounce-type solutions, which yield
G-invariant instanton configurations on those cosets. Periodic solutions on S^1
x G/H and dyons on iR x G/H are also given.Comment: 1+26 pages, 14 figures, 6 miniplot
Botulinum toxin A decreases neural activity in pain-related brain regions in individuals with chronic ocular pain and photophobia
IntroductionTo examine the effect of botulinum toxin A (BoNT-A) on neural mechanisms underlying pain and photophobia using functional magnetic resonance imaging (fMRI) in individuals with chronic ocular pain.MethodsTwelve subjects with chronic ocular pain and light sensitivity were recruited from the Miami Veterans Affairs eye clinic. Inclusion criteria were: (1) chronic ocular pain; (2) presence of ocular pain over 1 week recall; and (3) presence of photophobia. All individuals underwent an ocular surface examination to capture tear parameters before and 4–6 weeks after BoNT-A injections. Using an event-related fMRI design, subjects were presented with light stimuli during two fMRI scans, once before and 4–6 weeks after BoNT-A injection. Light evoked unpleasantness ratings were reported by subjects after each scan. Whole brain blood oxygen level dependent (BOLD) responses to light stimuli were analyzed.ResultsAt baseline, all subjects reported unpleasantness with light stimulation (average: 70.8 ± 32.0). Four to six weeks after BoNT-A injection, unpleasantness scores decreased (48.1 ± 33.6), but the change was not significant. On an individual level, 50% of subjects had decreased unpleasantness ratings in response to light stimulation compared to baseline (“responders,” n = 6), while 50% had equivalent (n = 3) or increased (n = 3) unpleasantness (“non-responders”). At baseline, several differences were noted between responders and non-responders; responders had higher baseline unpleasantness ratings to light, higher symptoms of depression, and more frequent use of antidepressants and anxiolytics, compared to non-responders. Group analysis at baseline displayed light-evoked BOLD responses in bilateral primary somatosensory (S1), bilateral secondary somatosensory (S2), bilateral anterior insula, paracingulate gyrus, midcingulate cortex (MCC), bilateral frontal pole, bilateral cerebellar hemispheric lobule VI, vermis, bilateral cerebellar crus I and II, and visual cortices. BoNT-A injections significantly decreased light evoked BOLD responses in bilateral S1, S2 cortices, cerebellar hemispheric lobule VI, cerebellar crus I, and left cerebellar crus II. BoNT-A responders displayed activation of the spinal trigeminal nucleus at baseline where non-responders did not.DiscussionBoNT-A injections modulate light-evoked activation of pain-related brain systems and photophobia symptoms in some individuals with chronic ocular pain. These effects are associated with decreased activation in areas responsible for processing the sensory-discriminative, affective, dimensions, and motor responses to pain
Status of the VERITAS Observatory
VERITAS, an Imaging Atmospheric Cherenkov Telescope (IACT) system for
gammma-ray astronomy in the GeV-TeV range, has recently completed its first
season of observations with a full array of four telescopes. A number of
astrophysical gamma-ray sources have been detected, both galactic and
extragalactic, including sources previously unknown at TeV energies. We
describe the status of the array and some highlight results, and assess the
technical performance, sensitivity and shower reconstruction capabilities.Comment: Submitted to Proceedings of "4th Heidelberg International Symposium
on High Energy Gamma-Ray Astronomy 2008
Ethylene supports colonization of plant roots by the mutualistic fungus Piriformospora indica
The mutualistic basidiomycete Piriformospora indica colonizes roots of mono- and dicotyledonous plants, and thereby improves plant health and yield. Given the capability of P. indica to colonize a broad range of hosts, it must be anticipated that the fungus has evolved efficient strategies to overcome plant immunity and to establish a proper environment for nutrient acquisition and reproduction. Global gene expression studies in barley identified various ethylene synthesis and signaling components that were differentially regulated in P. indica-colonized roots. Based on these findings we examined the impact of ethylene in the symbiotic association. The data presented here suggest that P. indica induces ethylene synthesis in barley and Arabidopsis roots during colonization. Moreover, impaired ethylene signaling resulted in reduced root colonization, Arabidopsis mutants exhibiting constitutive ethylene signaling, -synthesis or ethylene-related defense were hyper-susceptible to P. indica. Our data suggest that ethylene signaling is required for symbiotic root colonization by P. indica
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