The Critique of the Principle of Uniformitarianism and the Analysis of High School Earth Science Textbooks

1996Although uniformitarianism is widely recognized as the basic principle upon which the structure of historical geology has been erected, a closer investigation on the basis of present scientific knowledge and the philosophy of science reveals some of its invalid aspects. The concept of uniformitarianism was developed in a dual concept in Lyellian days. Substantive uniformitarianism (a testable theory of geologic change postulating uniformity of rates or material conditions) is false, ambiguous and stifling to hypotheses formation. Methodological uniformitarianism (a procedural principle asserting that former changes of the Earth's surface may be explained by reference to causes now in operation) belongs to the definition of science and is not unique to geology. Moreover, it also has some methodological defects in forming bold and novel working hypotheses. Methodological uniformitarianism today should take the form of a much older and more general scientific principle: Occam's Razor, the principle of simplicity. Accordingly, substantive uniformitarianism, an incorrect theory, should be abandoned. Methodological uniformitarianism, now a superfluous term, should be best confined to the historical roles in geology. In this connection, the presentation of uniformitarianism in high school textbooks was analyzed. It was revealed that text books were riddled with false and misleading statements as to what uniformitarianism means. Since uniformitarianism, as presented in many textbooks, is in direct contradiction to the philosophy of Inquiry learning, it is important to rethink the direction of uniformitarianism presentation in Earth Science curriculum development

A case of primary psoas abscess presenting as buttock abscess

Buttock abscess is a rare clinical manifestation from unusual extrapelvic extension of psoas abscess. A 48-year-old woman presented with painful swelling of the buttock with a sense of local heat. Magnetic resonance imaging revealed a large subfascial abscess over the glutei muscles and was traced into the intraabdominal cavity over the iliac wing to the psoas muscle. Both the psoas abscess and the buttock abscess were evacuated via separate approaches. Empirical antibiotic therapy was delivered for 3 weeks. After 6 months, no evidence of recurrence was found. Psoas abscess could be included in the differential diagnosis of buttock abscess

Origin of multi-level switching and telegraphic noise in organic nanocomposite memory devices.

The origin of negative differential resistance (NDR) and its derivative intermediate resistive states (IRSs) of nanocomposite memory systems have not been clearly analyzed for the past decade. To address this issue, we investigate the current fluctuations of organic nanocomposite memory devices with NDR and the IRSs under various temperature conditions. The 1/f noise scaling behaviors at various temperature conditions in the IRSs and telegraphic noise in NDR indicate the localized current pathways in the organic nanocomposite layers for each IRS. The clearly observed telegraphic noise with a long characteristic time in NDR at low temperature indicates that the localized current pathways for the IRSs are attributed to trapping/de-trapping at the deep trap levels in NDR. This study will be useful for the development and tuning of multi-bit storable organic nanocomposite memory device systems

A NUMERICAL STUDY ON THE OPEN WATER PERFORMANCE OF A PROPELLER WITH SINUSOIDAL PITCH MOTION

When a ship operates in waves, the ship moves with 6 degrees-of-freedom, and a propeller at the stern of the ship cannot avoid moving due to the ship motion. Therefore, it is important to analyse the propulsion performance while considering the ship motion in waves for efficient ship operation. The pitch motion of the ship has a dominant effect on the variation of the propeller performance and results in sinusoidal pitch motion of the propeller. In this study, a numerical analysis was done using a KP458 model propeller with a diameter of 10 cm, which was designed for the KLVCC2 body plan. The propeller performance was calculated using computational fluid dynamics (CFD) at several constant tilt angles. Numerical simulations were then conducted with sinusoidal pitch motion in several conditions of varying pitch angle. The variations of the thrust and torque of the propeller in sinusoidal pitch motion were compared with the results obtained in constant tilt angles

Identification and Interpretation: A Framework of Naturalistic Epistemology Perceived by Korean Pre-Service Science Teachers

Abstract The epistemology of science and teachers' perspectives on it have been major lines of investigation in science education research. The role that epistemology should play in science education has become increasingly relevant because of its incorporation within some important curriculum reform movements around the world. Improving teachers' perspectives and designing advanced teaching-learning sequences along them have been substantial parts of the science education reform. Such efforts are having been active when a new epistemological position emerged. The present inquiry has been conducted at the interface of these two lines of research. The main focus of the study is analyzing the way Korean pre-service teachers interpret epistemological aspects of scientific knowledge. A questionnaire to explore pre-service teachers' epistemological beliefs was developed for developing frameworks of naturalized epistemology. The questionnaire is composed of items using Likert scale and open-ended items. Two groups of pre-service teachers participated in this exploration: in an elementary teacher education universities and a secondary science teacher education university. Epistemological beliefs of prospective elementary teachers were identified through qualitative analysis of the answers to the open ended questions as well. Suggestions for curricula change and teaching-learning strategies being involved in the incorporation of scientific epistemology are considered

Rationale of decreasing low-density lipoprotein cholesterol below 70 mg/dL in patients with coronary artery disease: A retrospective virtual histology-intravascular ultrasound study

Background: The associations between statin and coronary plaque compositional changes were re­ported according to the use of high dose or not. An evaluation of the impact of low-density lipoprotein cholesterol (LDL-C) < 70 mg/dL by using real world dosages of statin on coronary plaque composition was undertaken. Methods: The study subjects consisted of 61 patients (mean 59.9 years old, 45 males) who underwent percutaneous coronary intervention, baseline and follow-up (F/U; mean 8.4 months) virtual histology- -intravascular ultrasound (VH-IVUS) examination. Change of plaque composition at peri-stent area, which was selected in order to measure the identical site at F/U study, was compared according to the F/U LDL-C level. Results: Body mass index, prevalence of dyslipidemia, baseline total cholesterol and baseline LDL-C were significantly lower in F/U LDL-C < 70 mg/dL group (14 segments in 10 patients) than F/U LDL-C ≥ 70 mg/dL group (79 segments in 51 patients). F/U high-density lipoprotein cholesterol (HDL-C, OR 1.06, 95% CI 1.00–1.11, p = 0.054) and F/U LDL-C < 70 mg/dL (OR 3.43, 95% CI 0.97–12.17, p = 0.056) showed strong tendency of regression of necrotic core volume (NCV) ≥ 10%. In multivariable logis­tic regression analysis, F/U HDL-C (OR 1.07, 95% CI 1.01–1.14, p = 0.020) and F/U LDL-C < 70 mg/dL (OR 8.02, 95% CI 1.58–40.68, p = 0.012) were the independent factors for regression of NCV ≥ 10%. Conclusions: Follow-up LDL-C level < 70 mg/dL with any types of statins and increase of HDL-C were associated with regression of NCV ≥ 10% in patients with coronary artery disease