7,864 research outputs found
Physical activity, academic and developmental measures in older primary school-children:A principal components analysis
Relationships between physical activity variables, developmental measures, socio-economic status, academic test scores, perceptual-motor tests and gender were examined for 261 year-six primary school students (137 females) with mean age = 12.3 years, SD = 0.3. Characteristics of child development were examined to identify those aspects most weighted towards academic performance. An exploratory principal components analysis with varimax rotation was undertaken. Principal components analysis showed that 59% of the variance in the data-set could be explained by four sub-types. Scores for perception of verticality of a rod against a tilted frame and for frontal plane semi-tandem dynamic postural stability loaded with scores for reading, writing, numeracy and socio-economic status on the first sub-type called the “Academic-Cognitive” component accounted for 22.24% of total variance with an eigenvalue of 3.3. Other components with Eigenvalues > 1 were “Pubescent Development”, “Fitness, Strength and Body Mass” and “Physical Activity and Motor Coordination”. The grouping of perceptual-motor and postural coordination tests with academic scores suggests possibilities for activities having synergy with academic performance and suggests further investigation to ascertain the extent of the associations
Teaching Christian Faith Integration in Psychological Assessment Courses
Within the existing literature that emphasizes the integration of faith and psychology, topics related to psychological assessment are rare inclusions. Yet, it is commonly recognized that assessment measures provide useful clinical infonnation. This article highlights the domain of psychological assessment as fertile ground for integrating psychology with spirituality. Three graduate-level faculty members who each teach psychological assessment courses in a clinical training program describe specific ways they integrate Christian faith and psychological assessment in the classroom. Foci for future efforts that would bring the areas of faith and psychological assessment together arc described along with some of the benefits such efforts would yield, especially for clinical practice
Glycerol production in plasmodium falciparum : towards a detailed kinetic model
Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Having caused the deaths of more than 10 million individuals since 2000 with
most of them occurring in Africa, malaria remains a serious disease that requires
undivided attention. To this end a detailed kinetic model of Plasmodium
falciparum glycolysis was constructed, validated and used to determine potential
drug targets for the development of novel, effective antimalarial therapies.
The kinetic model described the behaviour of the glycolytic enzymes with
a set of ordinary differential equations that was solved to obtain the steady
state fluxes and concentrations of internal metabolites. The model included a
glycerol branch represented in a single fitted equation. This present study set
out to detect, characterise, and incorporate into the model the enzymes that
constitute the glycerol branch of P. falciparum glycolysis.
The kinetic parameters of glycerol 3-phosphate dehydrogenase (G3PDH), the
first enzyme in the branch and catalyst of the dihydroxyacetone phosphosate
(DHAP) reducing reaction, was determined and added to the detailed kinetic model. The model was subsequently validated by comparing its prediction of
steady state fluxes with experimentally measured fluxes.
Once it was evident that the predictions of the unfitted model agreed with
experimentally measured fluxes, metabolic control analysis was performed on
this branched system to ascertain the distribution of control over the steady
state flux through the glycerol branch. The control G3PDH exercised over its
own flux was less than expected due to the enzyme’s sensitivity to changes in
NADH and thus the redox balance of the cell.
Attempts were made to detect the enzymes responsible for the conversion
of glycerol 3-phosphate (G3P) to glycerol. Very low levels of glycerol kinase
activity was observed. Although G3P-dependent release of inorganic phosphate
was detected results were inconclusive as to whether a non-specific phosphatase
also mediated the conversion.
Overall, the expansion of the model to include G3PDH did not affect the
steady state metabolite concentrations and flux adversely.AFRIKAANSE OPSOMMING: Vanaf die jaar 2000 het malaria die dood van meer as 10 miljoen mense veroorsaak.
Die meeste sterftes het in Afrika voorgekom —’n aanduiding van hoe
ernstige siekte dit is en een wat onverdeelde aandag moet geniet. Om hierdie
rede is ’n gedetaileerde kinetiese model van glikoliese in Plasmodium falciparum
gebou, gevalideer en gebruik om potensiële dwelm teikens te identifiseer
vir die ontwikkeling van nuwe, meer effektiewe anti-malaria terapieë.
Die kinetiese model beskryf die gedrag van die glikolitiese ensieme in terme
van gewone differensiële vergelykings wat opgelos is om die bestendige toestand
fluksies en interne metaboliet konsentrasies te bepaal. Die model sluit
’n gliserol-tak in wat deur ’n enkele aangepaste vergelyking verteenwoordig
word. Hierdie studie het voorgeneem om die ensieme van die gliserol-tak van P.
falciparum glikoliese te identifiseer, karakteriseer en in die model te inkorporeer.
Ons het die kinetiese parameters van die eerste ensiem in die gliserol-tak,
gliserol 3-fosfaat dehidrogenase (G3PDH), die katalis van die dihidroksiasetoon
fosfaat(DHAP) reduserende reaksie, bepaal. Die kinetiese parameters is by
die gedetaileerde model gevoeg. Validering het plaasgevind deur die model se
voorspellings met eksperimenteel bepaalde waardes te vergelyk.
Toe dit duidelik geword het dat die voorspellings van die model met die
eksperimenteel bepaalde fluks ooreenstem, is metaboliese kontrole analiese op
die vertakte sisteem uitgevoer. Dit is gedoen om vas te stel hoe die bestendige
toestand fluks deur die gliserol-tak beheer word. G3PDH het nie volle beheer
oor sy eie fluks nie, in teenstelling met ons vergewagtinge.
Daar is gepoog om vas te stel watter ensieme verantwoordelik is vir die produksie
van gliserol vanuit gliserol 3-fosfaat (G3P). ’n Lae gliserolkinase aktiwiteit
is waargeneem. Alhoewel G3P afhanklike vrystelling van anorganise fosfaat
waargeneem is, is dit nie duidelik vanuit die resultate of die proses deur ’n
nie-spesifieke fosfatase uitgevoer word nie.
Die uitbreiding van die model om ’n G3PDH vergelyking in te sluit het nie die
bestendige toestand metaboliet konsentrasies en fluks negatief geaffekteer nie
Application of Frontal Drive Principles to Stratified Reservoirs
Mechanical Engineerin
A circumferential slot virtual impactor for bioaerosol concentration
A virtual impactor aerosol concentrator with a circumferential inlet slot has been
built and tested. Circumferential slot virtual impactors (CSVIs) have low pressure
losses, similar to linear slot impactors, but without particle losses due to end effects.
The CSVI was designed using the results from a computational fluid dynamics
study. The device has a total sampling flow rate of 10 to 30 L/min and a concentration
factor of 10:1. CSVIs were built based on the CFD study design and tested with oleic
acid droplets and polystyrene latex beads. The test results found a cutpoint Stokes
number of 0.75 and 90% particle transmission at least 52X the Stokes cutpoint. At a
flow rate of 10 L/min the cutpoint is 2.0 µm aerodynamic diameter (AD) and >90%
transmission efficiency was found between 4 mm AD, and 22 µm AD. At the flow rate
of 30 L/min the cutpoint is 1.2 mm AD and a >90% transmission efficiency was found
between 2 and 10 mm AD. Performance and pressure drop curves were found for a
variety of flow rates. The pressure drop across the CSVI at 10 L/min was 270 Pa (1.1 in
H2O) with an ideal power consumption of 0.045 watts. At 30 L/min the pressure drop
was 970 Pa (3.9 in H2O) with an ideal power consumption of 0.44 watts
ANALYZING EXECUTIVE DECISIONMAKING PROCESSES: TILE METHODOLOGICAL CONTRIBUTION OF VISUAL MENTAL IMAGERY PROTOCOLS
Visual mental imagery protocols can provide step-by-step traces of executive decisionmaking. Sequences of drawings that externalize thought processes are often easier to analyze than transcriptions of tape recorded verbal protocols. The technique is of obvious use for investigating spatial problem solving behavior since such tasks are usually solved with sketches, drawings, or graphs; the methodology is also appropriate for abstract, non-spatial decisionmaking for which mental images often function as models that managers mentally construct and manipulate. This paper reports an application to the analysis of decisions by a high level executive: the commander of a naval task force. The study will influence both design and evaluation of the command and control systems that support tactical decision making by such commanders and their staffs, over long periods, in hostile environments under extreme stress
Recurrence of yield and protein variation in the northern grains region
Grain yield and protein maps of sorghum and wheat were collected over consecutive seasons at Jimbour (southern QLD) and at Gurley (northern NSW) to identify spatial and temporal changes in nitrogen (N) removal and N supply. The Jimbour site was cropped with sorghum for 3 years (1999-2001), and the Gurley site with wheat (1999) then fallowed into sorghum (2001). Grain yield variation was moderate to
high; coefficients of variation (CV) ranged from 12 to 30%. Protein variation was low for each site and season with CVs below 10%. At Jimbour, high applications of N fertiliser minimised temporal variation in grain protein. At Gurley, matching of N fertiliser with yield potential (based on soil depth) also resulted in a low temporal variation in protein. The low protein variation, both within seasons and between seasons, then contributed little to the temporal variations in N removal. Both sites had areas of stable variation but
low supplies of N; these were related to areas where moisture had pooled or where soil depth, and hence available soil moisture, limited yields. Unstable variation was associated with isolated trees, contour, or edge effects. Under these conditions, protein data may need to only be collected every 2-3 years
The Relationship between Narcotic Administration and Emergency Department Recidivism
The present study investigated the impact of narcotic administration on quantity and frequency of recidivism by patients presenting to the Emergency Department (ED) with a primary complaint of chronic pain. This study explored the relationship between narcotic administration, gender, prescribing physician and subsequent ED visits. We analyzed the data from the twelve months of medical records for 80 patients (278 visits) who presented at the ED of a general medical center in a rural area. Results indicated that the number of visits by those who received narcotics was significantly higher than for those who did not receive narcotics. There was also a significant difference in prescribing patterns, with females being more likely than males to receive a narcotic. Observable differences were found between the frequency of days between visits for those who received narcotics vs. those who did not, and the differential pattern of narcotic administration between providers. These findings raise the question that the receipt of a narcotic may reinforce visits to the ED. This study concluded that an established protocol for treating patients with chronic pain who present in the ED may be useful
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