scholarly journals Southern Africa: The Missing Piece To The Dust Provenance Puzzle of East Antarctica?

2021 ◽  
Author(s):  
Stefania Gili ◽  
Aubry Vanderstraeten ◽  
Amélie Chaput ◽  
James King ◽  
Diego Gaiero ◽  
...  
Keyword(s):  
Southern Africa ◽  
Source Area ◽  
East Antarctica ◽  
Atmospheric Composition ◽  
Dust Source ◽  
Geochemical Characterization ◽  
Potential Source ◽  
Natural Tracer ◽  
First Time

Abstract Mineral dust is a natural tracer of atmospheric composition and climate variability. Yet, there is still much to be known about the Southern Hemisphere dust cycle during the last Pleistocene. Major efforts have attempted to solve the ‘puzzle’ of the origin of the potential source areas that contribute dust to the Southern Ocean and East Antarctica (EA). Here we present a comprehensive geochemical characterization of an important potential source area, which role as a dust supplier to different environments of the SH has significantly been underestimated, that is, the Southern Africa (SAF) region. On the basis of Sr-Nd-Pb isotope ratios and rare earth element concentrations analyzed in sediments collected along the major dust-producing areas in the Namibian coast (Kuiseb, Omaruru and Huab riverbeds and the Namibian sand sea region), this study demonstrates for the first time that SAF emerges as the second most important dust source to EA during interglacial times.

FTIR time series of tropospheric HCN in eastern China and source attribution

2020 ◽  
Author(s):  
Youwen Sun ◽  
Pandai Dai ◽  
Hao Yin
Keyword(s):  
Eastern China ◽  
Atmospheric Composition ◽  
High Spectral Resolution ◽  
Source Attribution ◽  
Solar Absorption ◽  
Back Trajectories ◽  
Mauna Loa ◽  
Potential Source ◽  
Ftir Spectrometer ◽  
First Time

<p>We analyzed seasonality and interannual variability of tropospheric HCN column amounts in densely populated eastern China for the first time. The results were derived from solar absorption spectra recorded with ground-based high spectral resolution Fourier transform infrared (FTIR) spectrometer at Hefei (117°10′E, 31°54′N) between 2015 and 2018. The tropospheric HCN columns over Hefei, China showed significant seasonal variations with three monthly mean peaks throughout the year. The magnitude of the tropospheric HCN column peak in May > September > December. The tropospheric HCN column reached a maximum of (9.8 ± 0.78) × 10<sup>15</sup> molecules/cm<sup>2</sup> in May and a minimum of (7.16 ± 0.75) × 10<sup>15</sup> molecules/cm<sup>2</sup> in November. In most cases, the tropospheric HCN columns at Hefei (32°N) are higher than the FTIR observations at Ny Alesund (79°N), Kiruna (68°N), Bremen (53°N), Jungfraujoch (47°N), Toronto (44°N), Rikubetsu (43°N), Izana (28°N), Mauna Loa (20°N), La Reunion Maido (21°S), Lauder (45°S), and Arrival Heights (78°S) that are affiliated with the Network for Detection of Atmospheric Composition Change (NDACC). Enhancements of the tropospheric HCN columns were observed between September 2015 and July 2016 compared to the counterpart measurements in other years. The magnitude of the enhancement ranges from 5 to 46% with an average of 22%. Enhancement of tropospheric HCN (ΔHCN) is correlated with the coincident enhancement of tropospheric CO (ΔCO), indicating that enhancements of tropospheric CO and HCN were due to the same sources. The GEOS-Chem tagged CO simulation, the global fire maps and the PSCFs (Potential Source Contribution Function) calculated using back trajectories revealed that the seasonal maxima in May is largely due to the influence of biomass burning in South Eastern Asia (SEAS) (41 ± 13.1%), Europe and Boreal Asia (EUBA) (21 ± 9.3%) and Africa (AF) (22 ± 4.7%). The seasonal maxima in September is largely due to the influence of biomass burnings in EUBA (38 ± 11.3%), AF (26 ± 6.7%), SEAS (14 ± 3.3%), and Northern America (NA) (13.8 ± 8.4%). For the seasonal maxima in December, dominant contributions are from AF (36 ± 7.1%), EUBA (21 ± 5.2%), and NA (18.7 ± 5.2%).The tropospheric HCN enhancement between September 2015 and July 2016 at Hefei (32°N) were attributed to an elevated influence of biomass burnings in SEAS, EUBA, and Oceania (OCE) in this period. Particularly, an elevated fire number in OCE in the second half of 2015 dominated the tropospheric HCN enhancement in September – December 2015. An elevated fire number in SEAS in the first half of 2016 dominated the tropospheric HCN enhancement in January – July 2016.</p>

scholarly journals Molecular characterization of Cryptosporidium in calves from rural settlements in the Northwest region of the state of São Paulo, Brazil

2019 ◽  
Vol 40 (1) ◽  
pp. 491
Author(s):  
Lucas Vinicius Shigaki de Matos ◽  
Luiz Da Silveira Neto ◽  
Bruno César Miranda Oliveira ◽  
Miriam Yumi Makatu ◽  
Julia Cestari Pierucci ◽  
...  
Keyword(s):  
Sao Paulo ◽  
The State ◽  
Age Group ◽  
São Paulo ◽  
Rural Settlements ◽  
Potential Source ◽  
Stool Samples ◽  
Northwest Region ◽  
First Time

The study was conducted on 25 properties of the settlements São José I and Salvador, located in the municipalities of Brejo Alegre and Birigui, in the State of São Paulo, Brazil. A record of variables was elaborated and included data such as gender, breed and age of the animals. A total of 231 stool samples were collected from bovines aged one to six months, 128 being females and 103 males, 131 crossbred and 100 Holstein. Among the 231 samples, 17 (7.36%) were positive for Cryptosporidium spp. both by malachite green negative staining and by nested-PCR. Of the 17 positive samples, 14 were sequenced in agarose gel. These sequences were detected between 99% and 100% of genetic similarity for the following species. One sequence was similar to C. parvum (AB513880.1), one to C. bovis (MF074602.1), two to C. ryanae (KT922233.1), one to C. felis (KM977642.1) and nine were similar for C. andersoni reference MF350628. C. andersoni was found in animals aged 2–6 months, an age group which is different from those described by several authors. The presence of C. parvum indicates that the calves in the studied region should be considered a potential source for zoonotic transmission. For the first time to our knowledge, C. felis was identified in cattle in America.

scholarly journals First study of Cryptosporidium spp. occurrence in eared doves (Zenaida auriculata)

2019 ◽  
Vol 28 (3) ◽  
pp. 489-492
Author(s):  
Mércia de Seixas ◽  
Alessandra Taroda ◽  
Sérgio Tosi Cardim ◽  
João Pedro Sasse ◽  
Thais Agostinho Martins ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Protozoan Parasite ◽  
18S Rrna Gene ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Cryptosporidium Spp ◽  
Potential Source ◽  
Wide Range ◽  
First Time

Abstract Cryptosporidium is a protozoan parasite with a wide range of hosts, including humans. However, only a few Cryptosporidium species have been described in birds (C. meleagridis, C. baileyi, C. galli and C. avium). The aim of this study was to investigate the occurrence of Cryptosporidium spp. in feces of eared doves (Zenaida auriculata), followed by molecular characterization of the parasite. A total of 196 animals of both sexes were trap-captured; the animals were culled and the intestinal contents were collected for DNA extraction. After extraction, a nested-PCR (nPCR), which amplifies a fragment of the 18S rRNA gene of Cryptosporidium spp., was performed. The amplicons obtained were purified and sequenced. PCR analysis revealed that 30 animals (15.3%) were positive for Cryptosporidium spp. There was no significant sex-dependent enrichment of Cryptosporidium occurrence (p > 0.05). Only 15 out of the 30 positive samples were successfully sequenced and their species determined, of which, 13 (86.7%) and 2 (13.3%) were C. meleagridis and C. galli, respectively. Herein, we present for the first time a molecular characterization of Cryptosporidium from feces of eared doves (Z. auriculata) and propose that these birds are a potential source of C. meleagridis infection in humans.

scholarly journals Geochemical characterization of critical dust source regions in the American West

2017 ◽  
Vol 215 ◽  
pp. 141-161 ◽  
Author(s):  
Sarah M. Aarons ◽  
Molly A. Blakowski ◽  
Sarah M. Aciego ◽  
Emily I. Stevenson ◽  
Kenneth W.W. Sims ◽  
...  
Keyword(s):  
American West ◽  
Dust Source ◽  
Geochemical Characterization ◽  
Source Regions

TBE in Sweden

2020 ◽  
Keyword(s):  
Genetic Characterization ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Second Phase ◽  
Serum Samples ◽  
Tick Borne Encephalitis ◽  
Specific Immunoglobulin ◽  
Tick Borne Encephalitis Virus ◽  
First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

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