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- Huang, Xi, et al.
(author)
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Genetic diversity, temporal dynamics, and host specificity in blood parasites of passerines in north China.
- 2015
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In: Parasitology Reseach. - : Springer Science and Business Media LLC. - 1432-1955 .- 0932-0113. ; 114:12, s. 4513-4520
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Journal article (peer-reviewed)abstract
- Avian blood parasites have been preliminarily studied in East Asia, but no data are available from long-term monitoring. The aim of this study was to evaluate the prevalence, genetic diversity, and temporal dynamics of Plasmodium, Haemoproteus, and Leucocytozoon in two passerine communities (one forest and one urban) in north China from 2008 to 2013, as well as the association between infected lineages and host specificities. Out of 633 birds from 40 species, 157 individuals (24.8 %) were infected; overall prevalence was 26.7 % and 16.8 % in two sites, respectively. The dominant avian blood parasite genus in the forest park changed yearly between Plasmodium and Haemoproteus, while the Leucocytozoon maintained a low infection level. Forty-four haplotypes were identified by sequencing a 432-bp fragment of the cytochrome b (cyt b) gene; more than 70 % were novel (six Plasmodium lineages, 16 Haemoproteus lineages, and nine Leucocytozoon lineages). Based on our data gathered over consecutive years, we found that the highly observed lineages of Haemoproteus showed higher host diversities than those of Plasmodium, and the most infected lineage EMEL01 (100 % identity with SGS1) take on the highest host diversity but low temporal diversity of the two genera, implying that this lineage infected a great diversity of species in certain years, but maintained a lower infection level or even disappeared in other years. The results suggest that genetic diversity of avian blood parasites in East Asia is high and provides scope for further research. In addition, compared with overall analysis, yearly prevalence monitoring is important in uncovering the temporal dynamic and host specificity variations over time.
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2. |
- Jia, Ting, et al.
(author)
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Malaria parasites and related haemosporidians cause mortality in cranes : A study on the parasites diversity, prevalence and distribution in Beijing Zoo
- 2018
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In: Malaria Journal. - : Springer Science and Business Media LLC. - 1475-2875. ; 17:1
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Journal article (peer-reviewed)abstract
- Background: Malaria parasites and related haemosporidian parasites are widespread and may cause severe diseases in birds. These pathogens should be considered in projects aiming breeding of birds for purposes of sustained ex situ conservation. Cranes are the 'flagship species' for health assessment of wetland ecosystems, and the majority of species are endangered. Malaria parasites and other haemosporidians have been reported in cranes, but the host-parasite relationships remain insufficiently understood. Morbidity of cranes due to malaria has been reported in Beijing Zoo. This study report prevalence, diversity and distribution of malaria parasites and related haemosporidians in cranes in Beijing Zoo and suggest simple measures to protect vulnerable individuals. Methods: In all, 123 cranes (62 adults and 61 juveniles) belonging to 10 species were examined using PCR-based testing and microscopic examination of blood samples collected in 2007-2014. All birds were maintained in open-air aviaries, except for 19 chicks that were raised in a greenhouse with the aim to protect them from bites of blood-sucking insects. Bayesian phylogenetic analysis was used to identify the closely related avian haemosporidian parasites. Results: Species of Plasmodium (5 lineages), Haemoproteus (1) and Leucocytozoon (2) were reported. Malaria parasites predominated (83% of all reported infections). The overall prevalence of haemosporidians in juveniles was approximately seven-fold higher than in adults, indicating high susceptibility of chicks and local transmission. Juvenile and adult birds hosted different lineages of Plasmodium, indicating that chicks got infection from non-parent birds. Plasmodium relictum (pSGS1) was the most prevalent malaria parasite. Mortality was not reported in adults, but 53% of infected chicks died, with reports of co-infection with Plasmodium and Leucocytozoon species. All chicks maintained in the greenhouse were non-infected and survived. Species of Leucocytozoon were undetectable by commonly used PCR protocol, but readily visible in blood films. Conclusion: Crane chicks often die due to malaria and Leucocytozoon infections, which they likely gain from wild free-living birds in Beijing Zoo. Molecular diagnostics of crane Leucocytozoon parasites needs improvement. Because the reported infections are mainly chick diseases, the authors recommend maintaining of juvenile birds in vector-free facilities until the age of approximately 6 months before they are placed in open-air aviaries.
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3. |
- Wei, Chentao, et al.
(author)
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From the Himalayas to a continental Island : Integrative species delimitation in the Brownish-flanked Bush Warbler Horornis fortipes complex
- 2019
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In: Molecular Phylogenetics and Evolution. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 1055-7903 .- 1095-9513. ; 131, s. 219-227
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Journal article (peer-reviewed)abstract
- As species serve as basic units of study in many fields of biology, assessments of species limits are fundamental for such studies. Here, we used a multilocus dataset and different coalescent-based methods to analyze species delimitation and phylogenetic relationships in the Brownish-flanked Bush Warbler Horornis fortipes complex, which is widespread in the Sino-Himalayan region. We also examined the vocal and morphometric divergence within this complex. Our genetic results suggested that Horornis fortipes is composed of at least three independently evolving lineages, which diverged 1.1-1.8 million years ago. However, these lineages have hardly diverged in song or morphometrics and only very slightly in plumage. Our result indicate that there are three incipient species in Horonis fortipes complex diverged in central Himalayas and Hengduan Mountains, but not between the continent and Taiwan island.
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4. |
- Wei, Chentao, et al.
(author)
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The evolutionary origin of variation in song length and frequency in the avian family Cettiidae
- 2017
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In: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 48:10, s. 1295-1300
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Journal article (peer-reviewed)abstract
- Aspects of bird song have been shown to correlate with morphological and ecological features, including beak and body size, and habitat. Here we study evolution of song length and song frequency among 30 species belonging to the Cettiidae. Frequency is negatively correlated with body size, and song length increases with latitude. Although migration distance correlates with latitude, the association of song length with latitude is only present within the non-migratory species, implying the association is not a consequence of migration. We place these correlations in a historical framework to show that the body size-frequency association arose early in the group, but the latitude-song length association is more evolutionarily labile. We suggest that latitudinal correlates of song length may reflect increased importance of sexual selection by female choice.
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5. |
- Yang, Xichuan, et al.
(author)
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Improving the power conversion efficiency of solid state dye sensitized solar cells with a N-oxoammonium salt : 2,2,6,6-Tetramethyl-1-oxopiperidinebromide
- 2018
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In: Solar Energy. - : Pergamon Press. - 0038-092X .- 1471-1257. ; 170, s. 1001-1008
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Journal article (peer-reviewed)abstract
- P-type doping is a rational strategy for the enhancement of hole transporting properties of the organic semiconductors as well as the device performance of organic photo-electric devices. We originally introduce a stable and solution processed p-type dopant based on N-oxoammonium salts termed 2,2,6,6-tetramethyl-1-oxopiperidinebromide salt (TEMPO-Br) for 2,2',7,7'-tetrakis(N, N-di-p-methoxyphenyl-amine)9,9'-spirobifluorene (Spiro-OMeTAD) based solid state dye sensitized solar cells (ssDSC). By introducing TEMPO-Br doped Spiro-OMeTAD and a commercialized D-pi-A sensitizer into ssDSCs, a promising device performance of 6.83% is achieved under simulated AM 1.5G solar irradiation (100 mW cm(-2)), which is significantly better than the control devices ( similar to 1.7 times). The doping effect of TEMPO-Br on the photophysical and electrochemical properties of Spiro-OMeTAD, solid state device performance, cationic dye regeneration kinetics and preliminary long-term stability have been systematically investigated. This work indicates a potential application of N-oxoammonium salts as chemical P-type dopants for triphenylamine based hole transporting materials in solid state photo-electric devices.
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6. |
- Zhang, Yanyun, et al.
(author)
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DDQ as an effective p-type dopant for the hole-transport material X1 and its application in stable solid-state dye-sensitized solar cells
- 2018
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In: Journal of Energy Challenges and Mechanics. - : ELSEVIER SCIENCE BV. - 2056-9386. ; 27:2, s. 413-418
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Journal article (peer-reviewed)abstract
- X1 (MeO-TPD) is an inexpensive and easily synthesized pi-conjugated molecule that has been used as a hole-transport material (HTM) in solid-state dye-sensitized solar cells (ssDSSCs), achieving relatively high efficiency. In this paper, we characterize the physicochemical properties of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and show that it is a promising p-dopant in a spin-coating solution with X1 as the HTM. The doped ssDSSCs showed an increase in short-circuit current density from 5.38 mA cm(-2) to 7.39 mA cm(-2), and their overall power conversion efficiency increased from 2.9% to 4.3%. Also, ssDSSCs with DDQ-doped X1 were more stable than the undoped samples, demonstrating that DDQ can act as a p-type dopant in X1 as an HTM for highly efficient, stable ssDSSCs.
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