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Metacognition refers to the ability to evaluate and control our cognitive processes. While studies have investigated metacognition in schizophrenia and clinical high risk for psychosis (CHR), less is known about the potential mechanisms which result in metacognitive deficits.
We aimed to investigate whether neurocognitive functions including attention, working memory, verbal learning and executive functions predicted the tendency to focus on one’s thoughts (cognitive self-consciousness) and beliefs in the efficacy of one’s cognitive skills (cognitive confidence).
Participants (130 CHR individuals) were recruited as part of the multi-site PREDICT study. They were assessed using the Metacognitions Questionnaire (MCQ) as well as measures of executive function (WCST), attention (N-Back), working memory (LNS) and verbal learning (AVLT).
Cognitive competence was negatively correlated with N-Back while cognitive self-consciousness was positively correlated with N-Back and LNS. Linear regression analysis with N-Back, AVLT, LNS and WCST as predictors showed that neurocognition significantly predicted cognitive self-consciousness, with N-Back, LNS and WCST as significant predictors. The model accounted for 14% of the variance in cognitive self-consciousness. However, neurocognition did not result in a significant predictive model of cognitive competence.
Neurocognition was associated with an increased focus on one’s thoughts, but it was not associated with higher confidence in one’s cognitive skills. Neurocognition accounted for less than one-sixth of the variance in metacognition, suggesting that interventions that target neurocognition are unlikely to improve metacognitive abilities.
The in vitro nematicidal effect of Chenopodium ambrosioides and Castela tortuosa n-hexane extracts (E-Cham and E-Cato, respectively) on Haemonchus contortus infective larvae (L3) and the anthelmintic effect of these extracts against the pre-adult stage of the parasite in gerbils were evaluated using both individual and combined extracts. The in vitro confrontation between larvae and extracts was performed in 24-well micro-titration plates. The results were considered 24 and 72 h post confrontation. The in vivo nematicidal effect was examined using gerbils as a study model. The extracts from the two assessed plants were obtained through maceration using n-hexane as an organic agent. Gerbils artificially infected with H. contortus L3 were treated intraperitoneally with the corresponding extract either individually or in combination. The results showed that the highest individual lethal in vitro effect (96.3%) was obtained with the E-Cham extract at 72 h post confrontation at 40 mg/ml, followed by E-Cato (78.9%) at 20 mg/ml after 72 h. The highest combined effect (98.7%) was obtained after 72 h at 40 mg/ml. The in vivo assay showed that the individual administration of the E-Cato and E-Cham extracts reduced the parasitic burden in gerbils by 27.1% and 45.8%, respectively. Furthermore, the anthelmintic efficacy increased to 57.3% when both extracts were administered in combination. The results of the present study show an important combined nematicidal effect of the two plant extracts assessed against L3 in gerbils.
This cross-sectional study was undertaken to assess the status of school-based water, sanitation and hygiene (WASH) resources and soil-transmitted helminthiasis (STH) in Odeda, Ogun State, Nigeria. The status and condition of WASH resources were determined in eight selected schools (three with WASH support and five without). Stool samples were also collected from 428 pupils from both school categories and screened for STH infections. Findings showed that water and sanitation conditions of WASH resource programming schools were better than those in schools without WASH support. However, pupils’ knowledge about STH infections and basic hygiene were not significantly different between both categories of school (P > 0·05). The prevalence of Hookworm, Ascariasis and Trichuriasis cases recorded were 26·2, 18·2 and 1·6% respectively, with an overall prevalence of 33·4%. By school categories, Ascariasis (14·9 vs 20·6), Hookworm (17·7 vs 32·0), Trichuriasis (1·7 vs 1·6) and, any STH prevalence (27·4 vs 37·5) were recorded for schools with WASH resource programming and those without respectively. A greater portion of the infected children 95 (66·4%) were from schools without WASH support. Our findings imply that WASH resource may have very positive impact on the control of STH among school children. However, there is need for improvement on coverage, adequacy and maintenance of WASH facilities in school.
The propagation of cosmic ray protons and anti–protons from the inner Galaxy via the galactic halo to the Sun supplies a good agreement with the observed cosmic ray gradient and is in the order of the measured anti-proton flux. Ultra heavy cosmic ray nuclei may have the same origin.
The component of the frequency splitting of solar five-minute oscillations observed by Duvall, Harvey and Pomerantz that is even in azimuthal degree measures latitudinal and depth variations in the structure of the sun. We indicate how the data hint that there is a shallow perturbation, possibly associated with a magnetic field, that is concentrated at low latitudes.
A simple prescription for the dynamics of convection perturbed by stellar pulsation is used in an estimation of the growth rates of solar five-minute modes. Convection appears to enhance the excitation of the modes, and the maximum in the growth rate versus frequency found previously when oscillatory convective perturbations were ignored is still present.
Magnetic fields contribute to the splitting of the degeneracy of modes of like order and degree. The splitting is estimated for some simple hypothetical toroidal magnetic field configurations in the sun, and the results are compared with previous asymptotic estimates. Splitting by a field confined to a thin layer at the base of the convection zone is found not to agree with recent measurements.
The axis of rotation of the Sun's surface is inclined from the normal to the ecliptic by 7°.25. Is that true also of the rotation of the rest of the Sun? Knowledge of the direction of the angular momentum is pertinent to studies of the formation of the solar system. Moreover, Bai and Sturrock (1993) have recently interpreted temporal variations in the spatial distribution of solar flares as the outcome of the interaction of the Sun's envelope with an obliquely rotating core. We report here an attempt to determine the principal seismic axes of oscillation of the dipole and quadrupole p modes from LOI data obtained as a component of the VIRGO investigation on the spacecraft SOHO. We find that formally their most likely orientation is somewhat closer to being normal to the ecliptic than is the axis of the surface rotation. However, the uncertainty in the determination well encompasses the possibility of them being parallel to the surface rotation axis, yet it does not reject (at a level marginally greater than one standard deviation) the possibility that the Sun's angular momentum is parallel to that of the rest of the solar system.
We report the initial results of one year of continuous observations of the Sun‘s internal structure from the Michelson Doppler Imager (MDI) on board SOHO. The results have been obtained by inverting frequencies of p and f modes determined with two different methods of averaging over split multiplets. Small systematic differences between the two frequency sets depend primarily on mode frequencies, and, thus, did not significantly affect the inversions. A preliminary study of the systematic effects resulting from asymmetry of oscillation power peaks has also shown no significant influence on the inversion results. The inferred sound-speed profile is in general agreement with the previous data from MDI and ground-based networks. In the energy-generating core, the resolution is substantially improved, and the inversion results indicate a sharp negative perturbation of the sound speed in the core, tending to a positive value near the center. High-precision measurements of the f-mode frequencies have been used to determine the seismic radius of the Sun. The global asphericity estimated from frequency variation across the split mode multiplets has been found to be small, and is consistent with the asphericity during the previous activity minimum. Variations of the solar frequencies during the first year of MDI observations have also been detected.
Several techniques are available solely applicable to the study of inevitable endogenous flow or the digestibility of amino acids (AAs) at the terminal ileum. But the linear regression technique combines these tasks in one simple and flexible platform extendable to multifactorial evaluation of feedstuffs, for example under alternating dietary and physiological conditions. There is evidence that the amount and composition of inevitable endogenous flows are not constant. Also their estimates are dependent on assay protocols and other laboratory conditions. This variability is a drawback to methodological precision of the current conventional standardised digestibility (cSID) system, where inevitable endogenous flow is applied to correct apparent digestibility. Notably cSID may suffer systematic errors when used to assay low AA ingredients or those high in AAs and in anti-nutrients, leading to underestimation or overestimation of standardised digestibility, respectively. Thus a standardised system not encumbered by the need to determine inevitable flow should offer more latitude for precision. The latter approach is followed in linear regression. The linear regression approach is based on validated hypotheses both mathematical and physiological, which enable its ordinate intercept and slope respectively to be considered as inevitable endogenous flow and standardised digestibility. The literature shows that this method does not penalise ingredients low in AAs as its estimates are independent of dietary crude protein level; and it is efficient to determine standardised digestibility in feedstuffs which elevate the production of specific endogenous ileal AA flow. Nevertheless work remains to be done to standardise its protocols to improve comparability of data across investigations. It can be concluded that linear regression is a reliable path for routine determination of inevitable endogenous flow and standardised AA digestibility at the end of the ileum.
The Medium-l Program of the Michelson Doppler Imager (MDI) instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to ∼ 300. The initial results show that the noise in the Medium-l oscillation power spectrum is substantially lower than in ground-based measurements. This enables us to detect lower amplitude modes and, thus, to extend the range of measured mode frequencies. The MDI observations also reveal the asymmetry of oscillation spectral lines. The line asymmetries agree with the theory of mode excitation by acoustic sources localized in the upper convective boundary layer. The sound-speed profile inferred from the mean frequencies gives evidence for a sharp variation at the edge of the energy-generating core. In a thin layer just beneath the convection zone, helium appears to be less abundant than predicted by theory. Inverting the multiplet frequency splittings from MDI, we detect significant rotational shear in this thin layer.
This paper is an interim report of our inferences about the hydrostatic structure of the Sun, following the first report of the GONG team in Science (Gough et al., 1996). That work confirms that the spherically averaged structure of the Sun is more or less in agreement with current standard solar models. However, there remain some significant deviations which we regard as important clues to the existence of dynamical phenomena which are not taken into account in standard solar modelling.
Introduction: Minimizing haemorrhage using direct pressure is intuitive and widely taught. In contrast, this study examines the use of indirect-pressure, such as external aortic compression which has been identified as an immediately applicable maneuver to address the leading cause of battlefield mortality: junctional hemorrhage. However, it is currently unclear how to optimize this technique. Methods: This prospective, block-randomized, cross-over simulation study of compression optimization was performed on a model of central vessel compression that recorded weight (lbs) and pressure (mmHg). Forty participants simulated external aortic compression on the ground as well as a stretcher with and without a backboard. Participants were blinded to compression weight and pressure, as well as the purpose of the study, to minimize preparation bias. Manoeuvres were performed in alternating order to control for skill acquisition and fatigue. Scripted instructions were followed to compress with 1 then 2 hands, and to apply “sustainable effort” and then “maximal effort”. Results: The greater the compressor's bodyweight the greater their mean compression (Pearson’s correlation 0.9342). Using one-hand, a mean of 28% participant bodyweight (95%CI, 26% - 30%) could be transmitted at sustainable effort, waist-height, and on a stretcher. A second compressing hand increased rescuer bodyweight transmission by 10-22% regardless of other factors (i.e. presence/absence or a backboard; rescuer position) (p<0.001). Adding a backboard increased transmission of rescuer bodyweight 7%-15% (p<0.001). Lowering the patient from waist-height backboard to the floor increased transmission of rescuer bodyweight 4%-9% (p < 0.001). Kneeling on the model was the most efficient method and transmitted 11% more weight compared to two-handed maximal compression (p <0.001). Conclusion: Efficacy is maximized with larger-mass, two hands, and compression on hard surfaces/backboards. Knee compression is most effective and least fatiguing, thus assisting rescuers of lower weight and lesser strength, where no hard surfaces exist (i.e. no available backboard or trauma on soft ground), or when lengthy compression is required (i.e. remote locations). This study demonstrates the feasibility of indirect pressure as a potential temporizing measure for life-threatening haemorrhage not amenable to direct compression.
Ecological characteristics and environmental variation influence both host species composition and parasite abundance. Abiotic factors such as rainfall and temperature can improve parasite development and increase its reproduction rate. The comparison of these assemblages between different environments may give us a more refined analysis of how environment affects the variation of helminth parasite abundance. The aim of the present study was to evaluate how temporal variation, host size, sex and reproduction affect helminth abundance in the Tropidurus hispidus lizard in Caatinga, Restinga and Atlantic Forest environments. Overall, larger-sized lizards showed higher helminth abundance. We found a monthly variation in the helminth species abundance in all studied areas. In the Caatinga area, monoxenic and heteroxenic parasites were related to the rainy season and to the reproductive period of lizards. In Restinga, monoxenic and heteroxenic helminth species were more abundant during the driest months. In the Atlantic Forest, the rainy and host reproductive season occurred continuously throughout the year, so parasite abundance was relatively constant. Nevertheless, heteroxenic species were more abundant in this area. The present results showed that the temporal variation, body size, sex, reproductive period and habitat type influence the abundance and composition of helminth species in T. hispidus.
Helioseismology and asteroseismology put high demands on the accuracy and consistent numerical realization of the equation of state (for a review see Däppen, these proceedings). This is explicitly illustrated by the helioseismic determination of the helium abundance of the solar convection zone in a recent investigation by Kosovichev et al. (1992). In that work it was observed that details of the treatment of the heavy elements matter more than is intuitively expected. Naively, one would expect an uncertainty of less than 10−4 in the key thermodynamic quantity, the adiabatic gradient Γ1. This is because in material of solar composition the heavy-element abundance is less than about 1.5 × 10−3 by number, and under solar conditions the dominant nontrivial contributions to the seismically relevant thermodynamic quantities predicted by modern equations of state agree to a few per cent, even for the much more abundant hydrogen and helium. However, Kosovichev et al. (1992) found that uncertainties in the treatment of the heavy elements translate into discrepancies in Γ1 of the order of 10−3, which is enough to disturb the helioseismic helium-abundance determination significantly. We briefly present the reason below. A forthcoming paper will show more detailed results, though some further information can already be found in papers by Kosovichev et al. (1992) and Christensen–Dalsgaard & Däppen (1992).