scholarly journals Carbonaceous and siliceous Neoproterozoic vase-shaped microfossils (Urucum Formation, Brazil) and the question of early protistan biomineralization

2017 ◽  
Vol 91 (3) ◽  
pp. 393-406 ◽  
Author(s):  
Luana Morais ◽  
Thomas Rich Fairchild ◽  
Daniel J.G. Lahr ◽  
Isaac D. Rudnitzki ◽  
J. William Schopf ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Testate Amoebae ◽  
Manganese Ore ◽  
Santa Cruz ◽  
Geological Record ◽  
Carbonate Cement ◽  
Central Brazil ◽  
West Central ◽  
Basement Rocks ◽  
Neoproterozoic Glaciation

AbstractVase-shaped microfossils (VSMs) occur in dolomitic extraclasts of indeterminate provenance within the basal diamictite of the Neoproterozoic Urucum Formation (Jacadigo Group) of west-central Brazil, having an age constrained between 889±44 Ma (K-Ar; basement rocks) and 587±7 Ma (40Ar/39Ar age of early metamorphic cryptomelane in overlying manganese ore). Early isopachous carbonate cement entombed these VSMs, preserving rare direct evidence of original wall composition that is carbonaceous (now kerogenous) in practically all specimens. Some tests are siliceous or composed of a quartz-kerogen mixture; secondary replacement explains some features of these tests, but original biomineralization seems more likely for others. This interpretation, coupled with test morphology, suggests affinity to arcellinid testate amoebae. Five VSM taxa are recognized in the deposit:Cycliocyrillium simplexPorter, Meisterfeld, and Knoll, 2003, andC.torquataPorter, Meisterfeld, and Knoll, 2003, originally described in the Chuar Group (USA), and three new monospecific genera—Palaeoamphora urucumensen. gen. n. sp.,Limeta lageniformisn. gen. n. sp., andTaruma ratan. gen. n. sp. Most of the taxonomically important characteristics of these VSMs occur also in extant testate amoebae, but the combinations of some characters, such as organic-walled tests having exceptionally long necks that exhibit terminal apertures (L.lageniformisn. gen. n. sp.), are evidently novel additions to the known diversity of Neoproterozoic VSMs. Evidence of glacially influenced deposition in the conformably overlying Santa Cruz Formation may indicate that the Urucum Formation slightly preceded or was penecontemporaneous with a major Neoproterozoic glaciation, although the VSM-hosting extraclasts must be older, possibly rivaling the age of the testate amoebae of the Chichkan Formation (766±7 Ma) that are currently regarded as the oldest record of protists in the geological record.

scholarly journals The 2009 earthquake, magnitude mb 4.8, in the Pantanal Wetlands, west-central Brazil

2016 ◽  
Vol 88 (3) ◽  
pp. 1253-1264 ◽  
Author(s):  
FÁBIO L. DIAS ◽  
MARCELO ASSUMPÇÃO ◽  
EDNA M. FACINCANI ◽  
GEORGE S. FRANÇA ◽  
MARIO L. ASSINE ◽  
...  
Keyword(s):  
Earthquake Magnitude ◽  
Central Brazil ◽  
West Central

Geomorphological map of the Serra da Bodoquena karst, west-central Brazil

2007 ◽  
Vol 3 (1) ◽  
pp. 282-295 ◽  
Author(s):  
William Sallun Filho ◽  
Ivo Karmann
Keyword(s):  
Central Brazil ◽  
West Central ◽  
Geomorphological Map

scholarly journals Zika Virus Surveillance at the Human–Animal Interface in West-Central Brazil, 2017–2018

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1164 ◽  
Author(s):  
Alex Pauvolid-Corrêa ◽  
Helver Gonçalves Dias ◽  
Laura Marina Siqueira Maia ◽  
Grasiela Porfírio ◽  
Thais Oliveira Morgado ◽  
...  
Keyword(s):  
Real Time ◽  
Zika Virus ◽  
Whole Blood ◽  
Nucleotide Sequencing ◽  
Human Populations ◽  
Envelope Gene ◽  
Rt Pcr ◽  
Central Brazil ◽  
West Central ◽  
Virus Serotype

Zika virus (ZIKV) was first discovered in 1947 in Uganda but was not considered a public health threat until 2007 when it found to be the source of epidemic activity in Asia. Epidemic activity spread to Brazil in 2014 and continued to spread throughout the tropical and subtropical regions of the Americas. Despite ZIKV being zoonotic in origin, information about transmission, or even exposure of non-human vertebrates and mosquitoes to ZIKV in the Americas, is lacking. Accordingly, from February 2017 to March 2018, we sought evidence of sylvatic ZIKV transmission by sampling whole blood from approximately 2000 domestic and wild vertebrates of over 100 species in West-Central Brazil within the active human ZIKV transmission area. In addition, we collected over 24,300 mosquitoes of at least 17 genera and 62 species. We screened whole blood samples and mosquito pools for ZIKV RNA using pan-flavivirus primers in a real-time reverse-transcription polymerase chain reaction (RT-PCR) in a SYBR Green platform. Positives were confirmed using ZIKV-specific envelope gene real-time RT-PCR and nucleotide sequencing. Of the 2068 vertebrates tested, none were ZIKV positive. Of the 23,315 non-engorged mosquitoes consolidated into 1503 pools tested, 22 (1.5%) with full data available showed some degree of homology to insect-specific flaviviruses. To identify previous exposure to ZIKV, 1498 plasma samples representing 62 species of domestic and sylvatic vertebrates were tested for ZIKV-neutralizing antibodies by plaque reduction neutralization test (PRNT90). From these, 23 (1.5%) of seven species were seropositive for ZIKV and negative for dengue virus serotype 2, yellow fever virus, and West Nile virus, suggesting potential monotypic reaction for ZIKV. Results presented here suggest no active transmission of ZIKV in non-human vertebrate populations or in alternative vector candidates, but suggest that vertebrates around human populations have indeed been exposed to ZIKV in West-Central Brazil.

scholarly journals HUMAN PARASITISM BY Rhipicephalus sanguineus sensu lato (ACARI: IXODIDAE) IN MATO GROSSO DO SUL, WEST-CENTRAL BRAZIL

2017 ◽  
Vol 54 (1) ◽  
pp. 96 ◽  
Author(s):  
Igor Cunha Lima Acosta ◽  
Thiago Fernandes Martins ◽  
Marcelo Bahia Labruna
Keyword(s):  
Rhipicephalus Sanguineus ◽  
Mato Grosso ◽  
Central Brazil ◽  
West Central ◽  
Rhipicephalus Sanguineus Sensu Lato ◽  
Mato Grosso Do Sul

O parasitismo humano pelo carrapato marrom do cão, Rhipicephalus sanguineus sensu lato (s. l.), um importante parasita para a saúde pública e veterinária, é raramente relatado no continente americano. Este trabalho relata o registro de um macho de R. sanguineus s. l. parasitando um humano na cidade de Campo Grande, estado do Mato Grosso do Sul, no Centro-Oeste do Brasil. Essa observação é relevante para a saúde pública, uma vez que os carrapatos desse complexo são conhecidos como vetores de riquétsias do grupo da febre maculosa para cães e humanos.

scholarly journals Quaternary tufa in the Serra da Bodoquena Karst, West-Central Brazil: Evidence of wet period

2009 ◽  
Vol 6 (7) ◽  
pp. 072055 ◽  
Author(s):  
William Sallun Filho ◽  
I Karmann ◽  
A Ernandes Martins Sallun ◽  
K Suguio
Keyword(s):  
Central Brazil ◽  
West Central

Observed summer weather regimes and associated extreme precipitation over Distrito Federal, west-central Brazil

2014 ◽  
Vol 72 (12) ◽  
pp. 4835-4848 ◽  
Author(s):  
Yumiko Marina Tanaka da Anunciação ◽  
Detlef Hans-Gert Walde ◽  
Rosmeri Porfírio da Rocha
Keyword(s):  
Extreme Precipitation ◽  
Weather Regimes ◽  
Central Brazil ◽  
West Central ◽  
Distrito Federal
Sign in / Sign up

Export Citation Format

Share Document