4,454 research outputs found
The Effectiveness of the High-School Academic Program in Preparing Graduates for Post-Secondary Education as Perceived by Alumni From Four Seventh-day Adventist Senior High Schools in Canada
Problem. Questions have been raised regarding the preparation of high-school students for postsecondary studies. This study was designed to measure the effectiveness of the high-school academic program in preparing graduates for postsecondary education as perceived by alumni from four Seventh-day Adventist senior high schools in Canada.
Method. Respondents were asked to indicate their level of agreement for each of 18 statements on a Likert-type (survey) instrument, strongly disagree (1) to strongly agree (5), measured against a scale—I-2.5, minimally effective; 2.51-3.5, moderately effective; and 3.51-5, highly effective. Mean scores and standard deviation scores were calculated to answer the first research question. Four other research questions were answered by testing 90 hypotheses to determine their level of significance, using one-way Analysis of Variance (ANOVA). The standard set for rejecting the null hypotheses was any level of significance less than .05. The population size was 1,020, while the sample population was 204. Of the 204 survey forms that were mailed, a total of 82 respondents (29 males and 53 females) returned usable survey forms.
Results. The respondents perceived the academic program as mostly moderately effective in preparing graduates for postsecondary studies. There was a difference in perception of library facilities based on ethnic origin (p \u3c .008). There were differences in perception between those who did not take additional courses before attending college/university and those who took additional courses towards: library facilities (p \u3c .005), study habits (p \u3c .047), and academic preparation (p \u3c .015). Differences in perception occurred between those who attended college/university immediately after high school and those who did not attend immediately, and between those who attended private postsecondary institutions and those who attended public postsecondary institutions only towards: academic preparation for postsecondary studies (p \u3c .041) and (p \u3c .001). Finally, those who attended public postsecondary institutions perceived that courses were too difficult (p \u3c .011) in contrast to those who attended private postsecondary institutions.
Conclusions. There is a great deal of homogeneity in perception among students who attended four of the nine Seventh-day Adventist senior high schools in Canada regarding the effectiveness of the high-school academic program. However, gender did not affect the perception of alumni
Synthetic magnetism for photon fluids
We develop a theory of artificial gauge fields in photon fluids for the cases
of both second-order and third-order optical nonlinearities. This applies to
weak excitations in the presence of pump fields carrying orbital angular
momentum, and is thus a type of Bogoliubov theory. The resulting artificial
gauge fields experienced by the weak excitations are an interesting
generalization of previous cases and reflect the PT-symmetry properties of the
underlying non-Hermitian Hamiltonian. We illustrate the observable consequences
of the resulting synthetic magnetic fields for examples involving both
second-order and third-order nonlinearities
Process and reactor design for biophotolytic hydrogen production
The green alga Chlamydomonas reinhardtii has the ability to produce molecular hydrogen (H2), a clean and renewable fuel, through the biophotolysis of water under sulphur-deprived anaerobic conditions. The aim of this study was to advance the development of a practical and scalable biophotolytic H2 production process. Experiments were carried out using a purpose-built flat-plate photobioreactor, designed to facilitate green algal H2 production at the laboratory scale and equipped with a membrane-inlet mass spectrometry system to accurately measure H2 production rates in real time. The nutrient control method of sulphur deprivation was used to achieve spontaneous H2 production following algal growth. Sulphur dilution and sulphur feed techniques were used to extend algal lifetime in order to increase the duration of H2 production. The sulphur dilution technique proved effective at encouraging cyclic H 2 production, resulting in alternating Chlamydomonas reinhardtii recovery and H2 production stages. The sulphur feed technique enabled photobioreactor operation in chemostat mode, resulting in a small improvement in H2 production duration. A conceptual design for a large-scale photobioreactor was proposed based on these experimental results. This photobioreactor has the capacity to enable continuous and economical H 2 and biomass production using green algae. The success of these complementary approaches demonstrate that engineering advances can lead to improvements in the scalability and affordability of biophotolytic H2 production, giving increased confidence that H2 can fulfil its potential as a sustainable fuel of the future. © 2013 the Owner Societies
On Kalmbach measurability
summary:In this note we show that, for an arbitrary orthomodular lattice , when is a faithful, finite-valued outer measure on , then the Kalmbach measurable elements of form a Boolean subalgebra of the centre of
Isotope effect in quasi-two-dimensional metal-organic antiferromagnets
Although the isotope effect in superconducting materials is well-documented,
changes in the magnetic properties of antiferromagnets due to isotopic
substitution are seldom discussed and remain poorly understood. This is perhaps
surprising given the possible link between the quasi-two-dimensional (Q2D)
antiferromagnetic and superconducting phases of the layered cuprates. Here we
report the experimental observation of shifts in the N\'{e}el temperature and
critical magnetic fields (; ) in a Q2D organic molecular antiferromagnets on
substitution of hydrogen for deuterium. These compounds are characterized by
strong hydrogen bonds through which the dominant superexchange is mediated. We
evaluate how the in-plane and inter-plane exchange energies evolve as the
hydrogens on different ligands are substituted, and suggest a possible
mechanism for this effect in terms of the relative exchange efficiency of
hydrogen and deuterium bonds
Modifying gut integrity and microbiome in children with severe acute malnutrition using legume-based feeds (MIMBLE II): A Phase II trial
Measurement and modelling of mass diffusion coefficients for application in carbon dioxide storage and enhanced oil recovery
In this work, measurements were carried out by the Taylor dispersion method [1, 2] to determine the
mutual diffusion coefficient for CO2 in water or hydrocarbon at effectively infinite dilution.
Measurements were carried out for CO2 in water, hexane, heptane, octane, decane, dodecane,
hexadecane, cyclohexane, squalane and toluene at temperatures between 298 K and 423 K with
pressures up to 69 MPa. Measurements of CO2 diffusivity in different brines were also carried out by
13C pulsed-field gradient NMR
Anaemia and blood transfusion in African children presenting to hospital with severe febrile illness
BACKGROUND: Severe anaemia in children is a leading cause of hospital admission and a major cause of mortality in sub-Saharan Africa, yet there are limited published data on blood transfusion in this vulnerable group. METHODS: We present data from a large controlled trial of fluid resuscitation (Fluid Expansion As Supportive Therapy (FEAST) trial) on the prevalence, clinical features, and transfusion management of anaemia in children presenting to hospitals in three East African countries with serious febrile illness (predominantly malaria and/or sepsis) and impaired peripheral perfusion. RESULTS: Of 3,170 children in the FEAST trial, 3,082 (97%) had baseline haemoglobin (Hb) measurement, 2,346/3,082 (76%) were anaemic (Hb <10 g/dL), and 33% severely anaemic (Hb <5 g/dL). Prevalence of severe anaemia varied from 12% in Kenya to 41% in eastern Uganda. 1,387/3,082 (45%) children were transfused (81% within 8 hours). Adherence to WHO transfusion guidelines was poor. Among severely anaemic children who were not transfused, 52% (54/103) died within 8 hours, and 90% of these deaths occurred within 2.5 hours of randomisation. By 24 hours, 128/1,002 (13%) severely anaemic children had died, compared to 36/501 (7%) and 71/843 (8%) of those with moderate and mild anaemia, respectively. Among children without severe hypotension who were randomised to receive fluid boluses of 0.9% saline or albumin, mortality was increased (10.6% and 10.5%, respectively) compared to controls (7.2%), regardless of admission Hb level. Repeat transfusion varied from ≤2% in Kenya/Tanzania to 6 to 13% at the four Ugandan centres. Adverse reactions to blood were rare (0.4%). CONCLUSIONS: Severe anaemia complicates one third of childhood admissions with serious febrile illness to hospitals in East Africa, and is associated with increased mortality. A high proportion of deaths occurred within 2.5 hours of admission, emphasizing the need for rapid recognition and prompt blood transfusion. Adherence to current WHO transfusion guidelines was poor. The high rates of re-transfusion suggest that 20 mL/kg whole blood or 10 mL/kg packed cells may undertreat a significant proportion of anaemic children. Future evaluation of the impact of a larger volume of transfused blood and optimum transfusion management of children with Hb of <6 g/dL is warranted. Please see related article: http://dx.doi.org/10.1186/s12916-014-0248-5. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12916-014-0246-7) contains supplementary material, which is available to authorized users
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