774 research outputs found
An Examination of Intellectual Functioning, School Achievement, and Personality Characteristics of Male Juvenile Delinquents
Research in the area of juvenile delinquency has reported personality and background differences between delinquents who have committed certain types of offenses (Randolph, l96l; Mizushima and DeVos, 1967). The major purpose of this study was to examine the academic characteristics of certain classifications of delinquent offenders. Specifically, the incidences of three school-related problems and absence of any of these problems were compared for certain classifications of offenders. The comparisons that were made were group versus individual offenses, person versus property offenses, and actual aggressors versus threatened aggressors. A second aspect of the study involved a comparative investigation of the personality characteristics of juvenile offenders.
Ninety-nine 13-15 year old male offenders, committed to the state\u27s institutional correctional system for the first time, were enlisted as subjects. While awaiting disposition at a reception and diagnostic center, subjects were administered the Slosson Intelligence Test (SIT) as an individual intelligence measure and the High School Personality Questionnaire (HSPQ) as a personality measure. An assessment of academic achievement level was made on the basis of the Wide Range Achievement Test (WRAT), which was routinely administered by educational evaluators to all children passing through the reception and diagnostic center.
Subjects scoring 69 or less on the SIT were classified as psychometrically mentally retarded. A discrepancy model formula (bond and Tinker, 1973) was employed to identify underachievers and specific academic deficiencies. Delinquents scoring two or more years below expected achievement levels on all three subtests of the WRAT were classified as underachievers, while delinquents scoring below in only one or two subtests were classified as having specific academic deficiencies. The classification of a subject as to type of offender was made on the basis of his committing offense and reported history of offenses.
Nearly 90% of the subjects were classified as having school related problems. An examination of the results indicated that the only significant relationship between the school-related groups and the offense classifications was that underachievers were more likely to be group offenders than individual offenders. A trend was found indicating that delinquents with specific academic deficiencies were more likely to be individual offenders than group offenders. The results of the HSPQ revealed few differences among the four groups. Psychometrically mentally retarded delinquents indicated that they felt more socially isolated than delinquents from the other groups. Personality comparisons for offense groups revealed several findings: (l) group offenders appeared to be more self-assured and secure than individual offenders, (2) group offenders were more socially conforming and moralistic than individual offenders, (3) individual offenders appeared to be more intelligent than group offenders, (4) individual offenders were less serious than group offenders, (5) property offenders were found to be more emotionally stable and less easily upset than person offenders, and (6) person offenders were found to be more intelligent than property offenders
Radioactive method enables determination of surface areas rapidly and accurately
Radioactive krypton adsorption technique is used to determine the surface area of more than one sample of material simultaneously
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Comparison of different dietary sources of n-3 polyunsaturated fatty acids on immune response in broiler chickens
The study aims to research the effects of varied dietary sources of n-3 polyunsaturated fatty acids (PUFA) on the immune response in broiler chickens with stress on natural killer (NK) cell activity. Diets supplemented with one of the four sources of n-3 PUFA: linseed oil-, echium oil-, fish oil (FO) or algal biomass-enriched diets at levels of 18, 18, 50 and 15 g/kg fresh weight, were provided for one-d-old male Ross 308 broilers, totaling 340 in number, until they were slaughtered. The analyses included total lipid profile using gas chromatography (GC) for plasma, spleen, thymus, and blood. Additionally, NK cell activity and cell proliferation were investigated for thymocytes and splenocytes. The results indicated that the source of n-3 PUFA had a strong influence on fatty acid composition across all tissues. NK activity was highest in splenocytes and PBMCs from broilers fed linseed oil, followed by those fed algal biomass or echium oil, and lowest for those from broilers fed FO. The proliferative response of lymphocytes from algal biomass-fed chickens tended to be the highest, followed by those fed linseed oil in most cases. Lymphocytes from chickens fed fish oil showed the lowest proliferative response. These results could mean that a docosahexaenoic acid (DHA)-rich algal product might enrich chicken meat with n-3 PUFA without significant damaging effects on chicken immunity
Gravity changes and passive SO2 degassing at the Masaya caldera complex, Nicaragua
An understanding of the mechanisms responsible for persistent volcanism can be acquired through the integration of geophysical and geochemical data sets. By interpreting data on micro-gravity, ground deformation and SO2 flux collected at Masaya Volcano since 1993, it is now clear that the characteristically cyclical nature of the activity is not driven by intrusion of additional magma into the system. Rather, it may be due in large part to the blocking and accumulation of gas by restrictions in the volcano substructure. The history of crater collapse and formation of caverns beneath the crater floor would greatly facilitate the trapping and storage of gas in a zone immediately beneath San Pedro and the other craters. Another mechanism that may explain the observed gravity and gas flux variations is the convective overturn of shallow, pre-existing, degassed, cooled, dense magma that is replaced periodically by lower density, hot, gas-rich magma from depth. Buoyant gas-rich magma rises from depth and is emplaced near the surface, resulting in the formation and fluctuation of a low-density gas-rich layer centred beneath Nindirà and Santiago craters. As this magma vigorously degasses, it must cool, increase in density and eventually sink. Five stages of activity have been identified at Masaya since 1853 and the most recent data suggest that the system may have been entering another period of reduced degassing in 2000. This type of analysis has important implications for hazard mitigation because periods of intense degassing are associated with poor agricultural yields and reduced quality of life. A better understanding of persistent cyclically active volcanoes will allow for more effective planning of urban development and agricultural land use
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Magma transfer processes at persistently active volcanoes: insights from gravity observations
Magma transfer processes at persistently active volcanoes are distinguished by the large magma flux required to sustain the prodigious quantities of heat and gas emitted at the surface. Although the resulting degassed magma has been conjectured to accumulate either deep within the volcanic edifice or in the upper levels of the sub-edifice system, no direct evidence for such active accumulation has been reported. Temporal gravity data are unique in being able to quantify mass changes and have been successfully used to model shallow magma movements on different temporal scales, but have not generally been applied to the investigation of postulated long-term accumulation of magma at greater spatial scales within volcanic systems. Here, we model the critical data acquisition parameters required to detect mass flux at volcanoes, we review existing data from a number of volcanoes that exemplify the measurement of shallow mass changes and present new data from Poas and Telica volcanoes. We show that if a substantial proportion of degassed magma lodges within the sub-edifice region, it would result in measurable annual to decadal gravity increases occurring over spatial scales of tens of kilometres and propose that existing microgravity data from Sakurajima and, possibly, Etna volcanoes could be interpreted in these terms. Furthermore, such repeat microgravity data could be used to determine whether the accumulation rate is in equilibrium with the rate of production of degassed magma as calculated from the surface gas flux and hence identify the build-up of gas-rich magma at depth that may be significant in terms of eruption potential. We also argue that large magma bodies, both molten and frozen, modelled beneath volcanoes from seismic and gravity data, could represent endogenous or cryptic intrusions of degassed magma based on order of magnitude calculations using present-day emission rates and typical volcano lifetimes
Gravity and elevation changes at Askja, Iceland
Ground tilt measurements demonstrate that Askja is in a state of unrest, and that in the period 1988 - 1991 a maximum 48 +/- 3 µrad tilt occurred down towards the centre of the caldera. This is consistent with 126 mm of deflation at the centre of the caldera with a 2.5 - 3.0 km depth to the source of deformation. The volume of the subsidence bowl is 6.2 x 106 m3. When combined with high precision microgravity measurements, the overall change in sub-surface mass may be quantified. After correction for the observed elevation change using the free air gradient of gravity measured for each station, the total change in mass is estimated to be less than 109 kg. A small residual ground inflation and net gravity increase in the eastern part of the caldera may be caused by dyke intrusion in this region. The minimum dimensions of such an intrusion or complex of intrusions are 1m width, up to 100m deep and up to several hundred metres thick
Post-eruptive gravity changes from 1990 to 1996 at Krafla volcano, Iceland
The 1975–1984 Krafla rifting episode was a major lava- and dyke-producing event associated with the release of extensional strain accumulated over more than 200 years at the divergent plate boundary in North Iceland. The present work provides a unique example of gravity decreases and increases sustained over a long period following a major eruptive episode at a rift volcano. After height correction, persistent net gravity decreases over the source of observed Mogi-type deflation occur with gravity increases occurring further away from this centre of deformation. Gravity decreases are interpreted in terms of drainage from a shallow magma chamber. The net gravity decreases require that at least 4×1010 kg of magma must have been drained during the 6-year observation period. Assuming a density of 2700 kg m−3, this magma would occupy 1.5×107 m3 and by analogy with results obtained for Kilauea, this implies a magma chamber volume change of 4.1×106 m3. This is consistent with the chamber volume change deduced from ground deformation data assuming a Poisson's ratio of 0.25 and a Mogi source. Net gravity increases are more spatially extensive and are most likely caused by migration of the steam–water interface and/or closure of micro-fractures in lavas above the magma chamber during post-eruptive cooling and contraction. We present a model for the Krafla magma chamber in which a cooling, contracting and draining magma body causes subsidence at the surface. These results contrast with observations from the Askja caldera, Iceland, where post-eruptive deflation has been shown to be accompanied by negligible net gravity changes above the Mogi-type source in the caldera. Long-term post-eruptive deflation and magma drainage have not been observed at subduction-related volcanoes; this may be a function of a difference in magma viscosity
Discrete classification and electron energy spectra of Titan's varied magnetospheric environment
We analyse combined electron spectra across the dynamic range of both Cassini electron sensors in order to characterise the background plasma environment near Titan for 54 Cassini-Titan encounters as of May 2009. We characterise the encounters into four broad types: Plasma sheet, Lobe-like, Magnetosheath and Bimodal. Despite many encounters occurring close to the magnetopause only two encounters to date were predominantly in the magnetosheath (T32 and T42). Bimodal encounters contain two distinct electron populations, the low energy component of the bi-modal populations is apparently associated with local water group products. Additionally, a hot lobe-like environment is also occasionally observed and is suggestively linked to increased local pick-up. We find that 34 of 54 encounters analysed are associated with one of these groups while the remaining encounters exhibit a combination of these environments. We provide typical electron properties and spectra for each plasma regime and list the encounters appropriate to each. Citation: Rymer, A.M., H. T. Smith, A. Wellbrock, A.J. Coates, and D.T. Young (2009), Discrete classification and electron energy spectra of Titan's varied magnetospheric environment, Geophys. Res. Lett., 36, L15109, doi: 10.1029/2009GL039427
Interactions between imagined movement and the initiation of voluntary movement: A TMS study
Objective: The purpose was to examine motor imagery-induced enhancement in corticospinal excitability during a reaction time (RT) task. Methods: Nine young and healthy Subjects performed an isometric finger flexion tasks in response to a visual imperative cue. In the pre-cue period, they were instructed to: (I) rest; (2) imagine flexing their fingers isometrically (ImFlex): or (3) imagine extending their fingers isometrically (ImExt). Surface EMGs from the finger flexors and extensors were monitored to ensure EMG silence before movement onset. Transcranial magnetic stimulation (TMS) was used to evaluate changes in motor-evoked potentials (MEP) in the finger flexor and extensor muscles during the response phase. TMS was delivered either with the imperative cue, or 120 ms before and after the imperative cue. Results: RT was slower when they were imagining finger extension prior to the visual imperative cue. MEPs were significantly increased for the finger flexors during imagined finger flexion and for the finger extensors during imagined finger extension at both TMS delivery time points, reflecting movement specific enhancement in corticospinal excitability during motor imagery. When TMS was delivered 120 ms after the cue, finger flexor MEN were further facilitated under the Rest and ImFlex conditions, but not under the ImExt condition, suggesting additive interactions between imagery-induced enhancement and early rise in corticospinal excitability during the initiation of a reaction time response. Conclusions: Our results provide neurophysiological evidence mediating dynamic interactions between imagined movement and the initiation of voluntary movement. Significance: Motor imagery can be integrated into a rehabilitation protocol to facilitate motor recovery. (C) 2009 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved
On the Life History of Wire Worms of the Genus Agriotes, Esch., With Some Notes on that of Athous Haemorrhoidalis, F. Part I
RESP-26
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