Search

Zinc oxide (ZnO) is semiconductor with a wide band gap of 3.4 eV. It continues to gain more attention not only for its versatile use in industry but also its potential for further application in electronics, optics, spintronics, and transparent circuits. Many of these applications require p-type ZnO. Nitrogen substituting for oxygen is a possible acceptor for such applications. In this paper, we report a study of nitrogen-hydrogen (N–H) complexes grown into single-crystal ZnO, using seeded chemical vapor transport in an ammonia ambient. An infrared (IR) absorption peak arising from N–H complexes was observed at 3150.6 cm-1 at liquid-helium temperatures. The assignment of this peak was confirmed by nitrogen and hydrogen isotope substitution. Polarized IR spectroscopy shows that the N–H dipole is oriented at an angle ∼114° to the c axis, in agreement with previous first-principles calculations. To probe the stability of the N–H complexes, samples were annealed in air, oxygen, and argon. Samples annealed in oxygen at 725 °C showed a significant increase in resistivity, due to outdiffusion of hydrogen and compensation by nitrogen acceptors. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is a wide band gap semiconductor with potential applications in optoelectronics, transparent electronics, and spintronics. The high efficiency of UV emission in this material could be harnessed in solid-state white lighting devices. The problem of defects, in particular, acceptor dopants, remains a key challenge. In this review, defects in ZnO are discussed, with an emphasis on the physical properties of point defects in bulk crystals. As grown, ZnO is usually n-type, a property that was historically ascribed to native defects. However, experiments and theory have shown that O vacancies are deep donors, while Zn interstitials are too mobile to be stable at room temperature. Group-III (B, Al, Ga, and In) and H impurities account for most of the n-type conductivity in ZnO samples. Interstitial H donors have been observed with IR spectroscopy, while substitutional H donors have been predicted from first-principles calculations but not observed directly. Despite numerous reports, reliable p-type conductivity has not been achieved. Ferromagnetism is complicated by the presence of secondary phases, grain boundaries, and native defects. The famous green luminescence has several possible origins, including Cu impurities and Zn vacancies. The properties of group-I (Cu, Li, and Na) and group-V (N, P, As, and Sb) acceptors, and their complexes with H, are discussed. In the future, doping of ZnO nanocrystals will rely on an understanding of these fundamental properties. [ABSTRACT FROM AUTHOR]

In terms of the number of respondents, Survey on Well-Being among Foreign Born Population (FinMonik) is so far the most extensive survey carried out among the population with foreign background in Finland. It comprises a wide range of self-reported data, including information on the respondent's health, well-being and access to care, which can be widely utilized in planning and assessing integration, health and welfare policies. A mixed-method approach (an electronic questionnaire, a paper questionnaire and phone interviews) was used in collecting the data which consists of responses by 6836 respondents aged 18-64 years. All response types included, the response rate was 53.1% ( n = 6836). This study describes in detail the methods used in the FinMonik survey. In addition, we describe the demographics of the respondents partaking in each response format. The aim of the study is to promote the development of mixed-method survey as a way of collecting reliable data that can be used to enhance foreign-born people's health, well-being and access to health care. The survey responses will be used as a baseline in observing the respondents' well-being through the register-based data available in several national registers on health, medicine use and access to care as well as the data collected in the study Impact of Coronavirus Epidemic on Well-Being among Foreign Born Population Study (MigCOVID). Furthermore, the FinMonik study protocol will be repeated every four years.

Background: Since reproductive health is often considered a highly sensitive topic, underreporting in surveys and under coverage of register data occurs frequently. This may lead to inaccurate information about the reproductive health. This study compares the proportion of women having births and induced abortions among migrant women of Russian, Somali and Kurdish origin in Finland to women in the general Finnish population and examines the agreement between survey- and register-based data., Methods: The survey data from the Migrant Health and Wellbeing Study conducted in 2010-2012 and data from the Health 2011 Survey with corresponding information on women in the general population were used in this study. The respondents were women aged 18-64: 341 Russian, 176 Somali and 228 Kurdish origin women and 630 women in the general population. The survey data were linked to the Finnish Medical Birth Register and the Register of Induced Abortions., Results: In the combined (survey and register) data, migrant groups aged 30-64 had a higher proportion (89-96%) compared to the general population (69%) of women with at least one birth. Under-coverage of registered births was observed in all study groups. Among women aged 18-64, 36% of the Russian group and 24% of the Kurdish group reported more births in the survey than in the register data. In the combined data, the proportions of Russian origin (69%) and Kurdish origin (38%) women who have had at least one induced abortion in their lifetime are higher than in the general population (21%). Under-reporting of induced abortions in survey was observed among Somali origin women aged 18-29 (1% vs. 18%). The level of agreement between survey and register data was the lowest for induced abortions among the Somali and Russian groups (- 0.01 and 0.27)., Conclusion: Both survey- and register-based information are needed in studies on reproductive health, especially when comparing women with foreign origin with women in the general population. Culturally sensitive survey protocols need to be developed to reduce reporting bias.

The population of foreign origin in Finland is a heterogenic group, diverse for example with respect to reasons for and age at migration. While migration to Finland is a recent phenomenon, the size of the population of foreign origin has grown rapidly and will continue to increase. Changes in the population structure need to be taken into account in health promotion. For example lifestyle, health status, functional capacity, mental health, infectious diseases and reproductive health differ in foreign origin population compared with the general Finnish population. These differences may provide opportunities but also create challenges for service provision and health promotion planning.

Deinococcus geothermalis has frequently been isolated from pink colored deposits of paper industry processes. Laboratory studies have shown that D. geothermalis is capable of forming on nonliving surfaces patchy biofilms that are resistant to adverse agents such as extreme pH, desiccation, solubilising detergents and biocides. This study was done to quantitatively assess the role of D. geothermalis as a biofouler in paper industry. Colored deposits were collected from 24 European and North American paper and board machines and the densities of the bacterial 16S rRNA genes and those of the red slime producers D. geothermalis and Meiothermus spp. were measured by QPCR (quantitative real time PCR). D. geothermalis was found at nine machines, usually from splash area deposits, but its contribution was minor, 0.001-1%, to the total bacterial burden of 8.3 to log 10.5 log units per gram wet-weight of the deposits. When D. geothermalis was found in a measurable quantity, Meiothermus spp. also was found, often in bulk quantity (7-100% of the total bacteria). The data are in line with the properties of D. geothermalis known from laboratory biofilm studies, indicating this species is a pioneer coloniser of machine surfaces and may help other bacteria to adhere and grown into biofilms, rather than competing with them.

Colored biofilms cause problems in paper industry. In this work we used real-time PCR to detect and to quantitate members of the genus Meiothermus from the process samples and end products from 24 machines manufacturing pulp, paper and board in four countries. The results obtained from 200 samples showed the importance of members of the genus Meiothermus as ubiquitous biofoulers in paper machines. This genus was the dominant biofouler in some mills. From < or =10(4) to 10(11) copies of Meiothermus 16S rRNA genes were found per gram of process deposit (wet weight). Meiothermus spp. were found in paper and board products with colored defects and connection between deposit-forming microbes and end-product spots was shown. 16S rRNA gene sequences of 29 biofilm producing bacterial isolates from different mills were determined. Based on sequence data, 25 of the isolates were assigned to the genus Meiothermus, with Meiothermus silvanus and M. ruber as the most frequent species.

In this study, we examined the prevalence of Trichinella infection in domestic dogs in Finland, which is known to have a high prevalence of Trichinella infection in sylvatic hosts. Altogether 727 dog serum samples were tested serologically by ELISA with ES-antigen in dilutions 1:50, 1:100, 1:200, and 1:400. Additionally, muscle samples from 102 dogs' front leg extensors were tested parasitologically by HCl-pepsin-digestion. The tested dogs originated from the University Veterinary Hospital (244 of the sera and all of the parasitologically tested muscle samples) and from a serum bank of the National Veterinary and Food Research Institute (465 serum samples), representing healthy dogs mostly from southern Finland. As negative controls, we tested sera from 18 experimental dogs known to be negative for Trichinella infection. Trichinella spp. was isolated from one dog (1%) with a low infection intensity. High OD% were found in both groups of serum samples. Of the hospitalized dogs, 4.9% were classified positive, and 8.6% of the healthy dogs were classified positive (7.3% in total). The sex or breed of the tested dogs did not correlate with the positive results, but the age correlated positively in the serum bank group. The serological results suggest that dogs may be exposed to Trichinella spp. in Finland; however, confirmation of low-level infections requires confirmation by direct testing methods.

Genes tubb1 and tubb2 which encode beta-tubulins 1 and 2, respectively, were characterised from the ectomycorrhizal basidiomycete Suillus bovinus. The two beta-tubulins are surprisingly divergent, with the lowest known sequence identity (60%) in any single fungal species. Comparative analysis showed that beta-tubulin 1 and the intron distribution within the tubb1 gene resemble the other beta-tubulins. beta-Tubulin 2, in contrast, is the most divergent fully described fungal beta-tubulin and the gene contains at least 21 introns, which is the largest amount known for any beta-tubulin gene. Despite this divergence, both genes are constitutively expressed in the functional compartments of the mycorrhizosphere and in pure cultures. Transcription of tubb1 is about 2.4 times higher than that of tubb2; and this difference is also seen at the translation level. Evidence suggested that phosphorylation may be the main post-translational modification of both beta-tubulins. The putative GTP-binding site residues of beta-tubulin 1 match crystallised pig beta-tubulin residues, while five of the nine differences in beta-tubulin 2 match the pig alpha-tubulin GTP-site, suggesting the presence of adaptive sequence evolution. In a Bayesian analysis, beta-tubulin 1 joins the other basidiomycete sequences, while beta-tubulin 2 loosely associates with the group of divergent ascomycete sequences without any clear relative among the known full-length fungal beta-tubulin sequences.

•  Glutamine synthetase (GS) expression and activity is of central importance for cellular ammonium assimilation and recycling. Thus, a full characterization of this enzyme at the molecular level is of critical importance for a better understanding of nitrogen (N) assimilation in the mycorrhizal symbiosis. •  Genomic and cDNA libraries of Suillus bovinus were constructed to isolate the GS gene, glnA, and corresponding cDNAs. The transcription initiation site was identified and transcription and enzyme activities were characterized in pure culture mycelium and mycorrhiza, and extramatrical mycelium samples harvested from Scots pine-Suillus bovinus microcosms grown on forest humus. •  Pure culture mycelium, mycorrhiza and extramatrical mycelium all exhibited equivalent levels of GS transcription, translation and enzyme activities. However, levels of transcription and enzyme activity did not correlate as a large majority of detectable transcripts showed specific 5'-end truncation. •  Our data suggest that GS is constitutively expressed and not directly affected by environmental conditions of the symbiotic N uptake. Any changes in the intracellular ammonium level are most likely handled by regulatory flexibility of GS at enzyme level.