Proof in Mathematics Education, 1980-2020: An Overview

Gila Hanna,Chiristine Knipping 대한수학교육학회 2020 수학교육학연구 Vol.- No.특별호

This paper looks at the evolution of ideas on the role of proof in mathematics education from 1980 to 2020, examining in particular the contributions of both theoretical and empirical research to the teaching of mathematical proof. In so doing, it describes some of the major epistemological themes that emerged in the last forty years, primarily in the philosophy of mathematics and in mathematical education, and informed both the mathematics curriculum and research in mathematics education. The paper also discusses selected research studies that shed light on the opportunities and limitations students face when they engage in proof. Finally, it describes briefly a number of developments in proof technology and the potential of automated theorem provers for enhancing the teaching of proof.

A Phylogenetic Study of Korean Rodents (Muridae, Sciuridae) Based on Mitochondrial and Nuclear DNA

Gila Jung,Seo-Jin Lee,Chuel-kyu Kim,Hang Lee,Chang-Bae Kim 한국동물분류학회 2010 Animal Systematics, Evolution and Diversity Vol.26 No.2

The subfamily Murinae is a very controversial group concerning their phylogenetic relationship. Previous studies could not resolve phylogeny among four genera Apodemus, Micromys, Mus and Rattus of the Muridae. In the present study, eight rodent species resident in South Korea were collected and phylogenetically analyzed based on sequence data of five mitochondrial and nuclear DNA regions: 12S rRNA, cytochrome b gene (cyt b), cytochrome oxidase II (COII), control region of mitochondrial DNA, and a thyroglobulin (Tg) of nuclear DNA. According to the phylogeny of the concatenated data, M. musculus separated early in Murinae (ML 100%; BA 1.00 pp) and the genus Rattus grouped with the harvest mouse, M. minutes; these were separated from the genus Apodemus with relatively strong support (ML 74%; BA 0.76 pp). The Siberian chipmunk population was also examined using the five genes to obtain better resolution. The phylogeny for Korean rodents determined using the 12S rRNA, cyt b, COII and control regions discriminated the Siberian chipmunk populations from Korea, Russia, and China.

Complete mitochondrial genome of sea urchin: <i>Mesocentrotus nudus</i> (Strongylocentrotidae, Echinoida)

Jung, Gila,Choi, Hee-Jung,Pae, Sejin,Lee, Youn-Ho Informa Healthcare 2013 Mitochondrial DNA Vol.24 No.5

<P>The complete nucleotide of mitochondrial DNA of a sea urchin <I>Mesocentrotus nudus</I> was determined for the first time. It is 15,709 bp in length, containing 2 rRNA, 22 tRNA and 13 protein-coding genes generally found in other echinoderm species. The gene order and structure of the genome are identical to those of other Strongylocentrotidae species. The genome was composed of 29.3% A, 23.4% C, 29.5% T and 17.8% G, showing a slight AT bias (58.8%). The G is the least used base and markedly lower at the third codon position (12.74%). Twelve of the 13 mitochondrial protein-coding genes use ATG as their start codon while the <I>ATP8</I> gene starts with GTG. The control region is 125 bp in length and contains a G-stretch of 19 nucleotides, a typical DNA structure of the echinoid mitochondrial genomes.</P>

3D 변환을 위한 윈도우영상에서 사각 이미지 영역 검출

길종인(Jong In Gila),이준석(Jun Seok Leea),김만배(Manbae Kim) 한국방송·미디어공학회 2013 방송공학회논문지 Vol.18 No.6

In recent years, 2D-to-3D conversion techniques have gained much attraction. Most of conventional methods focused on natural images such as movie, animation and so forth. However, it is difficult to apply these techniques to window images mixed with text, image, logo, and icon. Also, different depth values of text pixels will cause distortion and a proper 3D image can not be delivered in some situations. To solve this problem, we propose a method to classify a given image into either a window or a natural image. For the window image, only rectangular image regions (RIR) are detected and converted in 3D. Other text and background are displayed in 2D. The proposed method was performed on more than 10,000 test images. In the experimental results, the detection ratio of window image reaches 97% and RIR detection ratio is 87%.

Brain-derived Neurotrophic Factor and High Sensitive C-reactive Protein in Bipolar Depression and Unipolar Depression: The Practical Usage as a Discriminatory Tool

Shima Shahyad(Shima Shahyad ),Gholam Reza Kheirabadi(Gholam Reza Kheirabadi ),Gila Pirzad Jahromi(Gila Pirzad Jahromi ),Muhammad Massaly(Muhammad Massaly ) 대한정신약물학회 2023 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.21 No.1

Objective: Brain-derived neurotrophic factor (BDNF) and high sensitive C-reactive protein (hs-CRP) have been reported to play roles in depression and bipolar disorder (BD). However, the probable discriminatory properties of these biologic markers are less investigated. We aimed to assess the serum BDNF and hs-CRP levels among Iranian patients with major depressive disorder (MDD) and BD during a depressive episode and investigate the optimum cut-off point for differential diagnosis of BD and MDD. Methods: We recruited 30 patients with MDD, 30 with BD in depressive mood and 30 healthy comparators. Blood sample was taken from each participant to measure BDNF and hs-CRP levels. We also used receiver operating characteristic (ROC) curve analysis to find an optimal cut-off point for differentiating MDD from BD according to pre-defined variables. Results: The mean age of total study population was 37.3 ± 5.0 years (males: 49%). BDNF was significantly lower in patients with BD, followed by MDD subjects and healthy controls 541.0 ± 601.0 pg/ml vs. 809.5 ± 433.3 pg/ml vs. 1,482.1 ± 519.8, respectively, p < 0.001). The area under curve of ROC curve analysis for BD versus MDD was 0.704 (95% confidence interval: 0.564−0.844, p = 0.007). We also found that the BDNF cut-off value of 504 could appropriately distinguished BD from MDD (sensitivity: 73%, specificity: 70%). No significant association were identified in terms of hs-CRP levels. Conclusion: Patients suffering from BD had lowest BDNF levels compared to MDD or healthy adults and this biomarker could play a practical role differentiating MDD from BD. Several studies are required confirming our outcomes.

Molecular Taxonomy of a Phantom Midge Species (Chaoborus flavicans) in Korea

Haein An,Gila Jung,Chang-Bae Kim 한국동물분류학회 2012 Animal Systematics, Evolution and Diversity Vol.28 No.1

The larvae of Chaoborus are widely distributed in lakes, ponds, and reservoirs. These omnivorous Chaoborus larvae are crucial predators and play a role in structuring zooplankton communities, especially for small-sized prey. Larvae of Chaoborus are commonly known to produce predator-induced polyphenism in Daphnia sp. Nevertheless, their taxonomy and molecular phylogeny are very poorly understood. As a fundamental study for understanding the role of Chaoborus in predator-prey interactions in a freshwater ecosystem, the molecular identification and phylogenetic relationship of Chaoborus were analyzed in this study. A molecular comparison based on partial mitochondrial cytochrome oxidase Ⅰ(COⅠ) between species in Chaoborus was carried out for the identification of Chaoborus larvae collected from 2 localities in Korea. According to the results, the Chaoborus species examined here was identified as C. flavicans, which is a lake-dwelling species. Furthermore, partial mitochondrial genome including COⅠ, COⅡ, ATP6, ATP8, COⅢ, and ND3 were also newly sequenced from the species and concatenated 5 gene sequences excluding ATP8 with another 9 dipteran species were compared to examine phylogenetic relationships of C. flavicans. The results suggested that Chaoborus was more related to the Ceratopogonidae than to the Culicidae. Further analysis based on complete mitochondrial DNA sequences and nuclear gene sequences will provide a more robust validation of the phylogenetic relationships of Chaoborus within dipteran lineages.

Progress in Novel Oxides for Gate Dielectrics and Surface Passivation of GaN/AlGaN Heterostructure Field Effect Transistors

Abernathy, C.R.,Gila, B.P.,Onstine, A.H.,Pearton, S.J.,Kim, Ji-Hyun,Luo, B.,Mehandru, R.,Ren, F.,Gillespie, J.K.,Fitch, R.C.,Seweel, J.,Dettmer, R.,Via, G.D.,Crespo, A.,Jenkins, T.J.,Irokawa, Y. The Institute of Electronics and Information Engin 2003 Journal of semiconductor technology and science Vol.3 No.1

Both MgO and $Sc_2O_3$ are shown to provide low interface state densities (in the $10^{11}{\;}eV^{-1}{\;}cm{\;}^{-2}$ range)on n-and p-GaN, making them useful for gate dielectrics for metal-oxide semiconductor(MOS) devices and also as surface passivation layers to mitigate current collapse in GaN/AlGaN high electron mobility transistors(HEMTs).Clear evidence of inversion has been demonstrated in gate-controlled MOS p-GaN diodes using both types of oxide. Charge pumping measurements on diodes undergoing a high temperature implant activation anneal show a total surface state density of $~3{\;}{\times}{\;}10^{12}{\;}cm^{-2}$. On HEMT structures, both oxides provide effective passivation of surface states and these devices show improved output power. The MgO/GaN structures are also found to be quite radiation-resistant, making them attractive for satellite and terrestrial communication systems requiring a high tolerance to high energy(40MeV) protons.

A role for endocannabinoids in acute stress-induced suppression of the hypothalamic-pituitary-gonadal axis in male rats

Karamikheirabad, Maryam,Behzadi, Gila,Faghihi, Mahdieh,Raoofian, Reza,Mehr, Shahram Ejtemaei,Zuure, Wieteke Ameliek,Sadeghipour, Hamid Reza The Korean Society for Reproductive Medicine 2013 Clinical and Experimental Reproductive Medicine Vol.40 No.4

Objective: Stress is known to be an inhibitor of the reproductive hypothalamic-pituitary-gonadal (HPG) axis. However, the neural and molecular connections between stress and reproduction are not yet understood. It is well established that in both humans and rodents, kisspeptin (encoded by the kiss1 gene) is a strong stimulator of the HPG axis. In the present study we hypothesized that endocannabinoids, an important neuromodulatory system in the brain, can act on the HPG axis at the level of kiss1 expression to inhibit reproductive function under stress. Methods: Adult male Wistar rats were unilaterally implanted with an intracerebroventricular cannula. Afterwards, the animals were exposed to immobilization stress, with or without the presence of the cannabinoid CB1 receptor antagonist AM251 (1 ${\mu}g/rat$). Blood samples were collected through a retro-orbital plexus puncture before and after stress. Five hours after the stress, brain tissue was collected for reverse transcriptase-quantitative polymerase chain reaction measurements of kiss1 mRNA. Results: Immobilization stress (1 hour) resulted in a decrease in the serum luteinizing hormone concentration. Additionally, kiss1 gene expression was decreased in key hypothalamic nuclei that regulate gonadotrophin secretion, the medial preoptic area (mPOA), and to some extent the arcuate nucleus (ARC). A single central administration of AM251 was effective in blocking these inhibitory responses. Conclusion: These findings suggest that endocannabinoids mediate, at least in part, immobilization stress-induced inhibition of the reproductive system. Our data suggest that the connection between immobilization stress and the HPG axis is kiss1 expression in the mPOA rather than the ARC.

Tracing hepatitis B virus to the 16th century in a Korean mummy

Kahila Bar‐,Gal, Gila,Kim, Myeung Ju,Klein, Athalia,Shin, Dong Hoon,Oh, Chang Seok,Kim, Jong Wan,Kim, Tae‐,Hyun,Kim, Seok Bae,Grant, Paul R.,Pappo, Orit,Spigelman, Mark,Shouval, Daniel Wiley Subscription Services, Inc., A Wiley Company 2012 Hepatology Vol.56 No.5

<P><B>Abstract</B></P><P>A rare find of a mummified child from the 16th century AD, in Korea, with relatively preserved organs, enabled a search for ancient hepatitis B virus (aHBV) DNA sequences from laparoscopic‐derived liver biopsies. Analysis of the complete aHBV genome (3,215 base pairs) revealed a unique HBV genotype C2 (HBV/C2) sequence commonly spread in Southeast Asia, which probably represents an HBV that infected the Joseon Dynasty population in Korea. Comparison of the aHBV sequences with contemporary HBV/C2 DNA sequences revealed distinctive differences along four open reading frames. Genetic diversity between contemporary and recovered aHBV/C2 DNA may be the result of immunologic, environmental, and/or pharmacologic pressures. The calculated time of most recent common ancestor suggests that the Korean HBV sequence origin dates back at least 3,000 years and possibly as long as 100,000 years. This isolate most likely represents the earliest human HBV sequence that colonized Southeast Asia by human migration. <I>Conclusion:</I> This study describes the complete sequence of the oldest HBV isolate and the most ancient full viral genome known so far. (H<SMALL>EPATOLOGY</SMALL> 2012;56:1671–1680)</P>

Measurement of band offsets in Y2O3/InGaZnO4 heterojunctions.

Park, Jong Cheon,Kim, Kyeong-Won,Gila, Brent P,Lambers, Eric S,Norton, David P,Pearton, Stephen J,Ren, Fan,Kim, Jin Kon,Cho, Hyun American Scientific Publishers 2014 Journal of Nanoscience and Nanotechnology Vol.14 No.11

<P>The valence band discontinuity (δE(v)) of Y2O3/InGaZnO4 (IGZO) heterojunctions was measured by a core-level photoemission method. The Y2O3 exhibited a band gap of -6.27 eV from absorption measurements. A value of δE(v) = 0.44 0.21 eV was obtained by using the Ga 2p3/2, Zn 2p3/2 and in 3d5/2 energy levels as references. Given the experimental bandgap of 3.2 eV for the IGZO, this would indicate a conduction band offset δE(c) of - 2.63 eV in the Y2O3/IGZO heterostructures and a nested interface band alignment.</P>