Electrical and magnetic properties of lead-substituted lanthanum ferrimanganites

The temperature dependences of the electrical conductivity, thermopower, and magnetoresistance for single crystals of lead-substituted lanthanum ferrimanganites are investigated. The data on the magnetic microstructure obtained by Mössbauer spectroscopy are analyzed. An inversion of the magnetoresistance sign with an increase in temperature and the giant positive magnetoresistance are found for one of the samples. The magnetoresistance quadratically depends on the field, and its temperature dependence exhibits a maximum. © 2000 MAIK "Nauka/Interperiodica"

Полиморфизмы некоторых генов у больных бронхиальной астмой жителей Красноярска

The aim of the study was to evaluate a role of transforming growth factor"β1 (TGF"β1) gene rs1800470 single nucleotide polymorphisms (SNPs), cytotoxic T"lymphocyte"associated protein 4 (CTLA4) gene rs231775 SNPs and hedgehog"interacting protein (HHIP) gene rs1828591 SNP for predisposition to bronchial asthma (BA) in Krasnoyarsk residents.Methods. The study involved 100 asthma patients and 338 control subjects. The control group included a representative population sample of Siberian urban residents without respiratory diseases who had participated in the WHO MONICA (Multinational Monitoring of Trends and Determinants in Cardiovascular Disease) and the HAPIEE (Health, Alcohol and Psychosocial factors In Eastern Europe) projects.Results. There was a significant difference in genotype and allele frequency distribution of the TGFβ gene in patients with non"allergic BA vs controls. Therefore, A allele carriers with heterozygous genotype AG and homozygous genotype AA of rs1800470 polymorphism of the TGF"β1 gene were at high risk of non"allergic BA. We also found an increase in the GG genotype frequency in BA group compared to the control group. The GG genotype of CTLA4 gene rs231775 polymorphism was associated with high risk of allergic BA (ОR = 2.036; 95% CI = 1.16–3.58; р = 0.012). Genotype and allele frequency distribution of HHIP gene rs1828591 polymorphism did not differ significantly between BA patients and the control group.Conclusion. An association was revealed between BA, TGF"β1 gene rs1800470 SNPs and CTLA4 gene rs231775 SNPs. An association between BA and HHIP gene rs1828591 SNPs was not found.Цель. Оценка вклада однонуклеотидных полиморфизмов (ОНП) rs1800470 гена трансформирующего фактора роста"β1 (TGF"β1), rs231775 гена цитотоксического Т"лимфоцит"связанного иммуноглобулина"4 (CTLA4) и rs1828591 белкового гена регуляции тканей (HHIP) в формирование предрасположенности к развитию бронхиальной астмы (БА) среди жителей Красноярска.Материалы и методы. В исследовании приняли участие больные БА (n = 100), а также популяционная выборка относительно здоровых жителей Новосибирска (n = 338) без бронхолегочной патологии, обследованных в рамках международных проектов MONICA (Multinational MONItoring of trends and determinants in CArdiovascular disease) и HAPIEE (Health, Alcohol and Psychosocial factors In Eastern Europe) в качестве контроля.Результаты. Выявлены существенные отличия в распределении частот генотипов и аллелей по гену TGF"β у больных неаллергической БА (НБА) в сравнении с контролем. У носителей аллеля А в гомозиготном (АА) и гетерозиготном (AG) вариантах полиморфизма rs1800470 гена TGF"β1 повышен риск развития НБА. При изучении полиморфизма rs231775 гена CTLA4 выявлено повышение частоты генотипа GG в группе больных аллергической БА (АБА), в т. ч. у женщин, по сравнению с группой контроля. Наличие генотипа GG rs231775 гена CTLA4 обусловливает повышенный риск развития АБА (отношение шансов – 2,036; 95%"ный доверительный интервал – 1,16–3,58; р1–3 = 0,012). Не выявлено значимых различий в распределении частот генотипов и аллелей rs1828591 гена HHIP у больных БА в сравнении с контролем.Заключение. Выявлена ассоциация с БА ОНП rs1800470 гена TGF"β1 и ОНП rs231775 гена CTLA4, ассоциация с БА ОНП rs1828591 гена HHIP не подтверждена

DESIGN AND DEVELOPMENT OF THE AFRICAN PLASMODIUM FALCIPARUM DATABASE – (afriPFdb)

The detailed investigation of mantle structure from the dispersion of surface waves is a young but vigorous field of study. Observations have been accumulating rapidly in the past few years because of the wide-spread installation of long-period instruments. Modern methods of data analysis used in conjunction with high-speed digital computers have made it possible to determine dispersion with greater precision and over a broader spectrum than has previously been possible. Observations now extend out to the fundamental periods of free oscillations of the whole earth. Interpretation has lagged behind observation because of the difficulties inherent in the problem of dispersion over realistic models of a spherical earth. This problem is now well in hand and dispersion appropriate to the standard earth models suggested by earlier body waves studies has been calculated. Even with digital computers, however, the computations are so formidable that until recently only the most tentative efforts have been made to modify the standard earth structures to give a more satisfactory fit to the data. A review as recent as the one by Bolt in the preceding volume of this series was, of necessity, limited to a discussion of the various standard earth models with no attempt made to use the full power of surface waves as an independent technique. Recent developments have made detailed surface wave interpretations possible and new information, rather than generalized verification of old information, should be rapidly forthcoming. Project Mohole and the International Upper Mantle Project have focused the attention of many earth scientists on the upper mantle. Because of this renewed emphasis present information and speculation on the properties of the mantle based on a variety of sources is summarized and re-examined in some detail. This provides the guide-lines for potentially fruitful further research and points out the nature of some of the discrepancies and limitations in our present knowledge that may be resolved by the surface wave method