Aang Aang | Alexandria University (original) (raw)
Papers by Aang Aang
In die eerste deel van die artikel word Psigolinguisties-relevante tipologieë van tweetaligheid b... more In die eerste deel van die artikel word Psigolinguisties-relevante tipologieë van tweetaligheid bespreek en sowel 'n driedelige semioties-genetiese tipologie as 'n metodologiese model vir beide ontwikkelings- en kultureel-georiënteerde taalnavorsing met strukturele en diskoersanalitiese benaderings word aange-bied. Ons beklemtoon die belangrikheid van die aard van tweetaligheid vir die studie van tweedetaalverwerwing gedu-rende die kinderjare. Verder word die noodsaaklikheid van omvattende navorsing oor tweetaligheid, waarin die toepassing van verskillende metodes mekaar komplementeer, beklemtoon. In die laaste gedeelte van die artikel word die resultate opgesom van 'n reeks epidemiologiese psigiatriese studies van tweetaligheid onder kinders van skool-gaande ouderdom wat van Swede na Noord-Finland terugkeer. Die studies is deur die ondersoekgroep van Moilanen, Myhrman & Kuure uitgevoer en die risiko's word uitgewys wanneer 'n oorspronklik homogene minderheidsgroep blootgestel word aan 'n situasie waar twee tale gemeng word, naamlik onderprestering op skool en emosionele ontwrigting. Aan die ander kant bevorder vaardigheid in beide tale en 'n duidelike tweetalige en bi-kulturele identiteit skoolprestasies en emosionele balans met die gevolg dat aanpassing by die nuwe omgewing gladweg verloop in 'n potensieel spanningsvolle immigrasiesituasie.In the first part of the article psycholinguistically relevant typologies of bilingualism are discussed, presenting a tripartite semiotic-genetic typology, as well as a methodological model for both developmentally and culturally-orientated linguistic research on bilingualism with structural and discourse analytical approaches. We emphasize the significance of the type of bilingualism for the study of the acquisition of a second language in childhood. Futhermore, we stress the need for comprehensive research on bilingualism in which applications of different methods complement one another. In the latter part of the article we summarize the results from a series of epidemiological psychiatric-linguistic studies of bilingualism among school-aged children returning from Sweden to Northern Finland which were conducted by the research group of Moilanen, Myhrman & Kuure. In the studies the risks involved in the mixed use of languages in originally monolingual minority homes were pointed out, leading in many cases to scholarly under-achievement and disturbances in emotional well-being. On the other hand, high proficiency in both languages as well as clear bilingual and bi-cultural identity enhance school-achievement and emotional well-being, resulting in a smooth adaptation to the new environment in a potentially stressing migration situation.
Plasma nitrite/nitrate levels reflect oxidation of formed nitric oxide (NO _ ) but are not indica... more Plasma nitrite/nitrate levels reflect oxidation of formed nitric oxide (NO _ ) but are not indicative of endothelial nitric oxide synthase (eNOS) function due to interference by dietary nitrates and reactive oxygen species (ROS). Nitrosyl hemoglobin (NOHb), a metabolic product of nitric oxide, may better correlate with bioavailable NO _ but it may depend on the activity of different nitric oxide synthase (NOS) isoforms and may be affected by dietary nitrite/nitrate. We examined the correlation between vascular endothelial NO _ release and circulating blood levels of NOHb. We measured NOHb in blood using electron spin resonance (ESR) spectrometry and also quantified vascular production of NO _ using colloid Fe(DETC) and ESR in mouse and human venous blood before and after treatment with the b -blocker carvedilol. Exclusively the inhibition with L-NAME and not the treatment with the selective neuronal nitric oxide synthase (nNOS) inhibitor, N-AANG or with the selective inducible nitric oxide synthase (iNOS) inhibitor, 1400W, halved NOHb formation, which reflects the complete inhibition of NO _ release by aortic endothelium. The relationship between NOHb and NO _ production by the endothelium (0.23 µM NOHb to 3.73 µM/hour of NO _ per mg of aorta dry weight) was found to be identical for both C57Blk/6 mice and for mice with vascular smooth muscle-targeted expression of p22phox associated with strong increase in eNOS activity. Furthermore, the treatment of patients with cardiovascular diseases with carvedilol for 3 weeks increases up to 2 times the circulating NOHb concentration. These results demonstrate the important role of eNOS in the formation of circulating NOHb and suggest that NOHb can be used as a noninvasive marker of endothelial NO _ production in vivo.
De juiste diagnose, classificatie en behandeling van thoraco-lumbale wervelfracturen blijven een ... more De juiste diagnose, classificatie en behandeling van thoraco-lumbale wervelfracturen blijven een problematisch en controversieël onderwerp in traumatologie. Een kort historisch overzicht (Hoofdstuk 1) laat zien dat de diagnose en behandeling van deze let-sels vaak hebben geleid tot hevige discussies en onenigheden. Voordat veilige en effectieve chirurgische technieken waren ontwikkeld, lag het centrum van de discussie in de vragen of een
IEEE Journal of Quantum Electronics, 1999
We describe experiments characterizing a new nonlinear optical crystal, YCa 4 O(BO 3 ) 3 (YCOB). ... more We describe experiments characterizing a new nonlinear optical crystal, YCa 4 O(BO 3 ) 3 (YCOB). This crystal has a number of advantages over other commonly available nonlinear optical crystals. It has a higher nonlinear coefficient than KDP, can be fabricated to large sizes (3-in diameter, 8-in length), and has a high damage threshold. Moreover, this new nonlinear optical crystal is nonhygroscopic, has good optical quality and mechanical properties, allowing easy optical polishing. This crystal, YCa4O(BO3)3, commonly termed YCOB, is one of a family of new nonlinear crystals, the oxyborates, that include RECa4O(BO3)3 (RE=La 3+ , Lu 3+ , Y 3+ , Sm 3+ , Gd 3+ , Er 3+ , and Nd 3+ ). In this paper, we also successfully demonstrate a technique for improving the nonlinear optical properties of this crystal. This technique, ion subsitution, has hetertofore had limited success with other crystal hosts. However, the inclusion of yttrium in YCOB provides the opportunity to exploit this technique. Yb 3+ , which has larger mass, but approximately the same atomic size as Y 3+ , can be substituted into the crystal structure without introducing stress and nonuniformities. A systematic investigation of the linear and nonlinear characteristics of several crystals doped with various levels of Yb demonstrate that selective substitution of Yb in YCa 4 O(BO 3 ) 3 improves the second-harmonic conversion efficiency by increasing the optical nonlinearity. Index Terms-Frequency conversion, nonlinear optical materials, nonlinear optics, rare-earth-doped materials, secondharmonic generation, YCa 4 O(BO 3 ) 3 .
IEEE Journal of Quantum Electronics, 1999
We describe experiments characterizing a new nonlinear optical crystal, YCa 4 O(BO 3 ) 3 (YCOB). ... more We describe experiments characterizing a new nonlinear optical crystal, YCa 4 O(BO 3 ) 3 (YCOB). This crystal has a number of advantages over other commonly available nonlinear optical crystals. It has a higher nonlinear coefficient than KDP, can be fabricated to large sizes (3-in diameter, 8-in length), and has a high damage threshold. Moreover, this new nonlinear optical crystal is nonhygroscopic, has good optical quality and mechanical properties, allowing easy optical polishing. This crystal, YCa4O(BO3)3, commonly termed YCOB, is one of a family of new nonlinear crystals, the oxyborates, that include RECa4O(BO3)3 (RE=La 3+ , Lu 3+ , Y 3+ , Sm 3+ , Gd 3+ , Er 3+ , and Nd 3+ ). In this paper, we also successfully demonstrate a technique for improving the nonlinear optical properties of this crystal. This technique, ion subsitution, has hetertofore had limited success with other crystal hosts. However, the inclusion of yttrium in YCOB provides the opportunity to exploit this technique. Yb 3+ , which has larger mass, but approximately the same atomic size as Y 3+ , can be substituted into the crystal structure without introducing stress and nonuniformities. A systematic investigation of the linear and nonlinear characteristics of several crystals doped with various levels of Yb demonstrate that selective substitution of Yb in YCa 4 O(BO 3 ) 3 improves the second-harmonic conversion efficiency by increasing the optical nonlinearity. Index Terms-Frequency conversion, nonlinear optical materials, nonlinear optics, rare-earth-doped materials, secondharmonic generation, YCa 4 O(BO 3 ) 3 .
In die eerste deel van die artikel word Psigolinguisties-relevante tipologieë van tweetaligheid b... more In die eerste deel van die artikel word Psigolinguisties-relevante tipologieë van tweetaligheid bespreek en sowel 'n driedelige semioties-genetiese tipologie as 'n metodologiese model vir beide ontwikkelings- en kultureel-georiënteerde taalnavorsing met strukturele en diskoersanalitiese benaderings word aange-bied. Ons beklemtoon die belangrikheid van die aard van tweetaligheid vir die studie van tweedetaalverwerwing gedu-rende die kinderjare. Verder word die noodsaaklikheid van omvattende navorsing oor tweetaligheid, waarin die toepassing van verskillende metodes mekaar komplementeer, beklemtoon. In die laaste gedeelte van die artikel word die resultate opgesom van 'n reeks epidemiologiese psigiatriese studies van tweetaligheid onder kinders van skool-gaande ouderdom wat van Swede na Noord-Finland terugkeer. Die studies is deur die ondersoekgroep van Moilanen, Myhrman & Kuure uitgevoer en die risiko's word uitgewys wanneer 'n oorspronklik homogene minderheidsgroep blootgestel word aan 'n situasie waar twee tale gemeng word, naamlik onderprestering op skool en emosionele ontwrigting. Aan die ander kant bevorder vaardigheid in beide tale en 'n duidelike tweetalige en bi-kulturele identiteit skoolprestasies en emosionele balans met die gevolg dat aanpassing by die nuwe omgewing gladweg verloop in 'n potensieel spanningsvolle immigrasiesituasie.In the first part of the article psycholinguistically relevant typologies of bilingualism are discussed, presenting a tripartite semiotic-genetic typology, as well as a methodological model for both developmentally and culturally-orientated linguistic research on bilingualism with structural and discourse analytical approaches. We emphasize the significance of the type of bilingualism for the study of the acquisition of a second language in childhood. Futhermore, we stress the need for comprehensive research on bilingualism in which applications of different methods complement one another. In the latter part of the article we summarize the results from a series of epidemiological psychiatric-linguistic studies of bilingualism among school-aged children returning from Sweden to Northern Finland which were conducted by the research group of Moilanen, Myhrman & Kuure. In the studies the risks involved in the mixed use of languages in originally monolingual minority homes were pointed out, leading in many cases to scholarly under-achievement and disturbances in emotional well-being. On the other hand, high proficiency in both languages as well as clear bilingual and bi-cultural identity enhance school-achievement and emotional well-being, resulting in a smooth adaptation to the new environment in a potentially stressing migration situation.
Plasma nitrite/nitrate levels reflect oxidation of formed nitric oxide (NO _ ) but are not indica... more Plasma nitrite/nitrate levels reflect oxidation of formed nitric oxide (NO _ ) but are not indicative of endothelial nitric oxide synthase (eNOS) function due to interference by dietary nitrates and reactive oxygen species (ROS). Nitrosyl hemoglobin (NOHb), a metabolic product of nitric oxide, may better correlate with bioavailable NO _ but it may depend on the activity of different nitric oxide synthase (NOS) isoforms and may be affected by dietary nitrite/nitrate. We examined the correlation between vascular endothelial NO _ release and circulating blood levels of NOHb. We measured NOHb in blood using electron spin resonance (ESR) spectrometry and also quantified vascular production of NO _ using colloid Fe(DETC) and ESR in mouse and human venous blood before and after treatment with the b -blocker carvedilol. Exclusively the inhibition with L-NAME and not the treatment with the selective neuronal nitric oxide synthase (nNOS) inhibitor, N-AANG or with the selective inducible nitric oxide synthase (iNOS) inhibitor, 1400W, halved NOHb formation, which reflects the complete inhibition of NO _ release by aortic endothelium. The relationship between NOHb and NO _ production by the endothelium (0.23 µM NOHb to 3.73 µM/hour of NO _ per mg of aorta dry weight) was found to be identical for both C57Blk/6 mice and for mice with vascular smooth muscle-targeted expression of p22phox associated with strong increase in eNOS activity. Furthermore, the treatment of patients with cardiovascular diseases with carvedilol for 3 weeks increases up to 2 times the circulating NOHb concentration. These results demonstrate the important role of eNOS in the formation of circulating NOHb and suggest that NOHb can be used as a noninvasive marker of endothelial NO _ production in vivo.
De juiste diagnose, classificatie en behandeling van thoraco-lumbale wervelfracturen blijven een ... more De juiste diagnose, classificatie en behandeling van thoraco-lumbale wervelfracturen blijven een problematisch en controversieël onderwerp in traumatologie. Een kort historisch overzicht (Hoofdstuk 1) laat zien dat de diagnose en behandeling van deze let-sels vaak hebben geleid tot hevige discussies en onenigheden. Voordat veilige en effectieve chirurgische technieken waren ontwikkeld, lag het centrum van de discussie in de vragen of een
IEEE Journal of Quantum Electronics, 1999
We describe experiments characterizing a new nonlinear optical crystal, YCa 4 O(BO 3 ) 3 (YCOB). ... more We describe experiments characterizing a new nonlinear optical crystal, YCa 4 O(BO 3 ) 3 (YCOB). This crystal has a number of advantages over other commonly available nonlinear optical crystals. It has a higher nonlinear coefficient than KDP, can be fabricated to large sizes (3-in diameter, 8-in length), and has a high damage threshold. Moreover, this new nonlinear optical crystal is nonhygroscopic, has good optical quality and mechanical properties, allowing easy optical polishing. This crystal, YCa4O(BO3)3, commonly termed YCOB, is one of a family of new nonlinear crystals, the oxyborates, that include RECa4O(BO3)3 (RE=La 3+ , Lu 3+ , Y 3+ , Sm 3+ , Gd 3+ , Er 3+ , and Nd 3+ ). In this paper, we also successfully demonstrate a technique for improving the nonlinear optical properties of this crystal. This technique, ion subsitution, has hetertofore had limited success with other crystal hosts. However, the inclusion of yttrium in YCOB provides the opportunity to exploit this technique. Yb 3+ , which has larger mass, but approximately the same atomic size as Y 3+ , can be substituted into the crystal structure without introducing stress and nonuniformities. A systematic investigation of the linear and nonlinear characteristics of several crystals doped with various levels of Yb demonstrate that selective substitution of Yb in YCa 4 O(BO 3 ) 3 improves the second-harmonic conversion efficiency by increasing the optical nonlinearity. Index Terms-Frequency conversion, nonlinear optical materials, nonlinear optics, rare-earth-doped materials, secondharmonic generation, YCa 4 O(BO 3 ) 3 .
IEEE Journal of Quantum Electronics, 1999
We describe experiments characterizing a new nonlinear optical crystal, YCa 4 O(BO 3 ) 3 (YCOB). ... more We describe experiments characterizing a new nonlinear optical crystal, YCa 4 O(BO 3 ) 3 (YCOB). This crystal has a number of advantages over other commonly available nonlinear optical crystals. It has a higher nonlinear coefficient than KDP, can be fabricated to large sizes (3-in diameter, 8-in length), and has a high damage threshold. Moreover, this new nonlinear optical crystal is nonhygroscopic, has good optical quality and mechanical properties, allowing easy optical polishing. This crystal, YCa4O(BO3)3, commonly termed YCOB, is one of a family of new nonlinear crystals, the oxyborates, that include RECa4O(BO3)3 (RE=La 3+ , Lu 3+ , Y 3+ , Sm 3+ , Gd 3+ , Er 3+ , and Nd 3+ ). In this paper, we also successfully demonstrate a technique for improving the nonlinear optical properties of this crystal. This technique, ion subsitution, has hetertofore had limited success with other crystal hosts. However, the inclusion of yttrium in YCOB provides the opportunity to exploit this technique. Yb 3+ , which has larger mass, but approximately the same atomic size as Y 3+ , can be substituted into the crystal structure without introducing stress and nonuniformities. A systematic investigation of the linear and nonlinear characteristics of several crystals doped with various levels of Yb demonstrate that selective substitution of Yb in YCa 4 O(BO 3 ) 3 improves the second-harmonic conversion efficiency by increasing the optical nonlinearity. Index Terms-Frequency conversion, nonlinear optical materials, nonlinear optics, rare-earth-doped materials, secondharmonic generation, YCa 4 O(BO 3 ) 3 .