115 research outputs found
Feeding of the probiotic bacterium Enterococcus faecium NCIMB 10415 differentially affects shedding of enteric viruses in pigs
Effects of probiotic bacteria on viral infections have been described
previously. Here, two groups of sows and their piglets were fed with or
without feed supplementation of the probiotic bacterium Enterococcus faecium
NCIMB 10415. Shedding of enteric viruses naturally occurring in these pigs was
analyzed by quantitative real-time RT-PCR. No differences between the groups
were recorded for hepatitis E virus, encephalomyocarditis virus and norovirus.
In contrast, astrovirus was exclusively detected in the non-supplemented
control group. Rotavirus was shedded later and with lower amounts in the
probiotic piglet group (p < 0.05); rotavirus-shedding piglets gained less
weight than non-infected animals (p < 0.05). Serum titres of anti-rotavirus
IgA and IgG antibodies were higher in piglets from the control group, whereas
no difference was detected between sow groups. Phenotype analysis of immune
cell antigens revealed significant differences of the CD4 and CD8β (p < 0.05)
as well as CD8α and CD25 (p < 0.1) T cell populations of the probiotic
supplemented group compared to the non-supplemented control group. In
addition, differences were evident for CD21/MHCII-positive (p < 0.05) and IgM-
positive (p < 0.1) B cell populations. The results indicate that probiotic
bacteria could have effects on virus shedding in naturally infected pigs,
which depend on the virus type. These effects seem to be caused by
immunological changes; however, the distinct mechanism of action remains to be
elucidated
Arylmethylamino steroids as antiparasitic agents
In search of antiparasitic agents, we here identify arylmethylamino steroids as potent compounds and characterize more than 60 derivatives. The lead compound 1o is fast acting and highly active against intraerythrocytic stages of chloroquine-sensitive and resistant Plasmodium falciparum parasites (IC50 15?nM) as well as against gametocytes. In P. berghei-infected mice, oral administration of 1o drastically reduces parasitaemia and cures the animals. Furthermore, 1o efficiently blocks parasite transmission from mice to mosquitoes. The steroid compounds show low cytotoxicity in mammalian cells and do not induce acute toxicity symptoms in mice. Moreover, 1o has a remarkable activity against the blood-feeding trematode parasite Schistosoma mansoni. The steroid and the hydroxyarylmethylamino moieties are essential for antimalarial activity supporting a chelate-based quinone methide mechanism involving metal or haem bioactivation. This study identifies chemical scaffolds that are rapidly internalized into blood-feeding parasites
Modelling economic impacts of deficit irrigated maize in Brazil with consideration of different rainfall regimes
Deficit irrigation is often required to cope with droughts and limited water availability.
However, to select an appropriate irrigation management, it is necessary to assess when
economic impacts of deficit irrigation are acceptable. Thus, the main goal of this study was
to evaluate economic water productivity for maize submitted to various levels of water
deficits and different irrigation systems. The study was based on two different experiments
conducted in Southern Brazil, one using sprinkler irrigation to supplement rainfall and the
other using drip irrigation with precipitation excluded by a rainfall shelter to simulate
cultivation under dry conditions. Water productivity indicators were calculated referring
to: a) actual field collected data, including yields, commodity prices and production costs;
and b) a sensitivity analysis to commodity prices and production costs. Alternative centrepivot
irrigation scenarios were also developed to assess their feasibility in terms of water
use and productivity when irrigation is used to supplement rainfall or when rainfall is
scarce. Results show that the feasibility of deficit irrigation is highly influenced by commodity
prices and by the irrigation (and water) costs when the irrigation costs are a large
part of the production costs. Results also show that deficit irrigation applied when rainfall
is abundant is easier to implement than deficit irrigation where rainfall is very scarce,
when only a mild stress is economically viable. For well-designed and managed centrepivot
systems, results confirm that adopting deficit irrigation when rainfall is scarce is
less attractive than under conditions of irrigation to supplement rainfall. It could be
concluded that farmers are unlikely to choose a deficit irrigation strategy unless they are
facing reduced water availability for irrigatio
Genetic and Biological Characteristics of Species A Rotaviruses Detected in Common Shrews Suggest a Distinct Evolutionary Trajectory
Species A rotaviruses (RVAs) are important etiological agents of severe diarrhea in young children. They are also widely distributed in mammals and birds, and increasing evidence indicates the possibility of zoonotic transmission of RVA strains between animals and humans. Moreover, reassortment of the eleven segments of the RVA genome can result in rapid biological changes and may influence pathogenic properties. Here, the nearly complete genome of an RVA strain from a common shrew (Sorex araneus) was sequenced, which showed high nucleotide sequence similarity to additionally determined partial sequences from common shrew RVAs, but only very low identity (below 68%) to RVAs from other animal species and humans. New genotypes were assigned to most genome segments of the novel common shrew RVA strain KS14/269 resulting in the genome constellation G39-P[55]-I27-R26-C22-M22-A37-N26-T26-E30-H26. Phylogenetic analyses clustered the common shrew RVAs as ancestral branches of other mammalian and avian RVAs for most of the genome segments, which is in contrast to the phylogeny of the hosts. Nevertheless, conserved sequences typical for all RVAs were identified at the 5ʹ- and 3ʹ- non-coding segment termini. To explore, whether the common shrew RVA can exchange genetic material with other mammalian RVAs by reassortment, a reverse genetics system based on the simian RVA strain SA11 was used. However, no viable reassortants could be rescued by exchanging the VP4-, VP6- or VP7-encoding genome segment alone or in combinations. It can be concluded that highly divergent RVAs are present in common shrews indicating an evolution of these viruses largely separated from other mammalian and avian RVAs. The zoonotic potential of the virus seems to be low, but needs to be further analyzed in future
Hepatitis E virus antibody prevalence in hunters from a district in Central Germany, 2013: a cross-sectional study providing evidence for the benefit of protective gloves during disembowelling of wild boars
Background: In Germany, 17 % of the general human population have antibodies to hepatitis E virus (HEV) (recomLine HEV-IgG/IgM immunoassay [Mikrogen GmbH]). Wild boars represent an animal reservoir for HEV genotype 3, which is the common genotype in Germany. We estimated the seroprevalence among hunters with contact to wild boars to identify factors that may be associated with past or present HEV infection. Methods: In 2013, the local veterinarian authority in a district in Central Germany attended meetings of hunters who provided blood specimens and completed a questionnaire collecting information on age, sex, hunting-related activities and consumption of wild boar meat. Specimens of wild boars were taken during drive hunts in this district during the season 2012/2013. All specimens were tested for HEV RNA and anti-HEV IgM and IgG antibodies. Log-binomial regression was used to estimate prevalence ratios (PR) for the hunters. Results: Of 126 hunters (median age 55; 94 % male) 21 % tested positive for anti-HEV IgG antibodies (95 % confidence interval [CI] 13–28 %) (recomWell HEV IgG assay [Mikrogen GmbH]). Anti-HEV prevalence was highest in the age group of the 70–79-year-olds (67 %; 95 % CI 39–95 %). Wild boars showed an average anti-HEV prevalence of 41 %. HEV RNA was detected in 4/22 (18 %) liver specimens and in 1/22 (4.5 %) muscle specimens. Most wild boars were tested positive for HEV RNA (3/10; 30 %) and HEV-specific antibodies (7/15; 47 %) in the southwestern part of the district. Hunters preferring this hunting ground had a lower anti-HEV prevalence when gloves were frequently used during disembowelling of wild boars compared to hunters using gloves never or infrequently (age-adjusted PR 0.12; 95 % CI 0.02–0.86). Conclusions: Hunters may benefit from wearing gloves when in contact with blood or body fluids of HEV animal reservoirs. Anti-HEV prevalence among the hunters of this study did not significantly differ from that of the general population suggesting that other factors play a major role in the epidemiology of HEV in Germany
Modelling soil water dynamics of full and deficit drip irrigated maize cultivated under a rain shelter
Research PaperThe model HYDRUS-1D was used to simulate soil water dynamics of full and deficit irrigated
maize grown under a rainout shelter during two crop seasons. Four irrigation treatments
were established based on the amount of water applied to fulfil crop water requirements.
Treatment D1 was irrigated to fully satisfy crop water requirements, while treatments D2
(mild deficit), D3 (moderate deficit), and D4 (severe deficit) were for increased controlled
water stress conditions. The computation and partitioning of evapotranspiration data into
soil evaporation and crop transpiration was carried out with the SIMDualKc model, and then
used with HYDRUS-1D. The soil hydraulic properties were determined from numerical
inversion of field water content data. The compensated root water uptake mechanism was
used to describe water removal by plants. TheHYDRUS-1D model successfully simulated the
temporal variability of soil water dynamics in treatments irrigated with full and deficit irrigation,
producing RMSE values that varied between 0.014 and 0.025 cm3 cm 3 when
comparing model simulations with field measurements. Actual transpiration varied between
224 and 483 mm. Potential transpiration reductions varied from 0.4 to 48.8% due to
water stress, but plants were able to compensate for the water deficits in the surface layers by
removing more water from the deeper, less stressed layers. HYDRUS-1D water balance estimates
were also comparable with the corresponding ones determined with the SIMDualKc
water balance model. Both modelling approaches should contribute to improve the webbased
IRRIGA system, used to support farm irrigation scheduling in Brazilinfo:eu-repo/semantics/publishedVersio
Hepatitis E virus genome detection in commercial pork livers and pork meat products in Germany
The hepatitis E virus (HEV) is one of the most common causes of hepatitis worldwide. HEV is also widespread in many developed countries, where the number of infections is steadily increasing. In those countries, the virus is transmitted mainly through consumption of undercooked or raw food or through contact with animals. Especially, pigs serve as a main reservoir of HEV. Here, we investigated the prevalence of HEV RNA in pork livers and pork meat products to assess the actual risk of HEV infection through food consumption in Germany. A total of 131 pork products were collected from grocery stores and butcher shops between October 2019 and February 2020 and screened for HEV RNA using nested PCR and subsequent sequencing. Overall, 10% of the samples were positive for HEV, including pork livers (5%), spreadable liver sausages (13%) and liver pâté samples (15%). Sequence analyses indicated that the large majority of HEV strains belonged to subtype HEV-3c, representing the most frequent subtype in Germany. One sample belonged to subtype HEV-3f. Further sequence analysis revealed large sequence variation between the samples; however, most of the mutations identified were synonymous. Although infectivity of the virus was not tested, the results suggest a considerable risk of HEV infection through food consumption. Therefore, preventive measures should be taken according to a One Health approach.Peer Reviewe
Mineralogical study of the Gonçalo Li-pegmatite deposit, Portugal
Beside the Scandinavian countries and Serbia, Portugal is among the European countries with the most significant lithium resources. The Li-rich occurrences in Portugal are mainly associated with aplite-pegmatite dykes and sills intruded in granitic and metasedimentary rocks of the Central Iberian and Galicia – Trás-os-Montes geotectonic zones (Carvalho & Farinha, 2004). The Gonçalo Li-pegmatites in the Guarda district (currently only used as decorative stone) have significant economic importance. Among other deposits, Gonçalo is a reference site in the focus of the EU FAME project (www.fame-project.eu) that aims to unlock the development potential of the most promising European Sn-W-Li ore types. Results of optical microscopy, QEMSCAN©, Raman and electron-probe microanalysis of the Gonçalo Li-pegmatite deposit have been employed to determine the mineralogical variability of the pegmatites with the aim to determine the deportment of lithium and potential rare-metal by-products and to guide enhanced mineral processing technologies.Available to download freely and reproduced here with permission of the publisher. The attached file is the published pdf
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