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951.
Abstract The palatability to common carp, Cyprinus carpio L. of three newly developed differently flavoured floating pellets made from a high proportion (40%) of brewer's spent grain (BSG) was tested using a multiple-offer feeding experiment. The addition of ‘bold’ flavours, such as vanilla or strawberry essence, may help mask the unpleasant taste of some piscicides; however, their inclusion must not compromise uptake by carp. There were no significant differences between the consumption rates of the three varieties, and all flavours were readily consumed. Therefore, it is suggested that highly flavoured pellets made with BSG have a strong potential to mask the flavour of an unpalatable toxin, and further research is now needed to test this hypothesis. 相似文献
952.
The carnivorous plant family Sarraceniaceae comprises three genera of wetland-inhabiting pitcher plants: Darlingtonia in the northwestern United States, Sarracenia in eastern North America, and Heliamphora in northern South America. Hypotheses concerning the biogeographic history leading to this unusual disjunct distribution are controversial, in part because genus- and species-level phylogenies have not been clearly resolved. Here, we present a robust, species-rich phylogeny of Sarraceniaceae based on seven mitochondrial, nuclear, and plastid loci, which we use to illuminate this family's phylogenetic and biogeographic history. The family and genera are monophyletic: Darlingtonia is sister to a clade consisting of Heliamphora+Sarracenia. Within Sarracenia, two clades were strongly supported: one consisting of S. purpurea, its subspecies, and S. rosea; the other consisting of nine species endemic to the southeastern United States. Divergence time estimates revealed that stem group Sarraceniaceae likely originated in South America 44-53 million years ago (Mya) (highest posterior density [HPD] estimate = 47 Mya). By 25-44 (HPD = 35) Mya, crown-group Sarraceniaceae appears to have been widespread across North and South America, and Darlingtonia (western North America) had diverged from Heliamphora+Sarracenia (eastern North America+South America). This disjunction and apparent range contraction is consistent with late Eocene cooling and aridification, which may have severed the continuity of Sarraceniaceae across much of North America. Sarracenia and Heliamphora subsequently diverged in the late Oligocene, 14-32 (HPD = 23) Mya, perhaps when direct overland continuity between North and South America became reduced. Initial diversification of South American Heliamphora began at least 8 Mya, but diversification of Sarracenia was more recent (2-7, HPD = 4 Mya); the bulk of southeastern United States Sarracenia originated co-incident with Pleistocene glaciation, <3 Mya. Overall, these results suggest climatic change at different temporal and spatial scales in part shaped the distribution and diversity of this carnivorous plant clade. 相似文献
953.
Olga V. Lisitsyna Sheila Hicks Antti Huusko 《Vegetation History and Archaeobotany》2012,21(3):187-199
Moss polsters, pollen traps and lake surface sediment samples are commonly used as climate calibration data or as modern analogues for reconstructing vegetation from fossil profiles, but the differences in pollen content between these media have received little attention. This study aims to analyse how the three media differ in reflecting individual vegetation types and spatial differences in vegetation. 119 modern samples (64 moss polsters, 37 lake surface sediment samples and 18 pollen traps from which a collection was made annually) were taken from northern Fennoscandia and the Kola Peninsula as a broad transect crossing the northernmost forest limits of Betula pubescens ssp. czerepanovii (mountain birch), Pinus sylvestris (Scots pine) and Picea abies (Norway spruce). The pollen assemblages from these samples were compared with the surrounding vegetation visually and via PCA (principle components analysis) and cluster analysis. Both comparisons allow a correct distinction between pollen assemblages of arctic/alpine heath, mountain birch dominated areas, and boreal coniferous forests. The differences between the vegetation zones are stronger than the differences between the sampling media. Nevertheless, lake sediment samples from the mountain birch woodland zone tend to overestimate pine and underestimate birch. Pollen traps are biased towards lower tree pollen percentages and higher values of shrubs, herbs and Cyperaceae. This bias is especially strong in traps that have missing years in the data. Irrespective of the vegetation zone, pollen traps tend to have lower Pinus pollen percentages than in the adjacent moss polsters. 相似文献
954.
955.
Capture and transfer of simian immunodeficiency virus by macaque dendritic cells is enhanced by DC-SIGN 总被引:5,自引:0,他引:5 下载免费PDF全文
Yu Kimata MT Cella M Biggins JE Rorex C White R Hicks S Wilson JM Patel PG Allan JS Colonna M Kimata JT 《Journal of virology》2002,76(23):11827-11836
Dendritic cells (DCs) are among the first cells encountered by human and simian immunodeficiency virus (HIV and SIV) following mucosal infection. Because these cells efficiently capture and transmit virus to T cells, they may play a major role in mediating HIV and SIV infection. Recently, a C-type lectin protein present on DCs, DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), was shown to efficiently bind and present HIV and SIV to CD4(+), coreceptor-positive cells in trans. However, the significance of DC-SIGN for virus transmission and pathogenesis in vivo remains unclear. Because SIV infection of macaques may represent the best model to study the importance of DC-SIGN in HIV infection, we cloned and characterized pig-tailed macaque DC-SIGN and generated monoclonal antibodies (MAbs) against it. We demonstrate that, like human DC-SIGN, pig-tailed macaque DC-SIGN (ptDC-SIGN) is expressed on DCs and macrophages but not on monocytes, T cells, or B cells. Moderate levels of ptDC-SIGN expression were detected on the surface of DCs, and low-level expression was found on macrophages. Additionally, we show that ptDC-SIGN efficiently binds and transmits replication-competent SIVmne variants to CD4(+), coreceptor-positive cells. Moreover, transmission of virus between pig-tailed macaque DCs and CD4(+) T cells is largely ptDC-SIGN dependent. Interestingly, MAbs directed against ptDC-SIGN vary in the capacity to block transmission of different SIVmne variants. These data demonstrate that ptDC-SIGN plays a central role in transmitting virus from macaque DCs to T cells, and they suggest that SIVmne variants may differ in their interactions with ptDC-SIGN. Thus, SIVmne infection of pig-tailed macaques may provide an opportunity to investigate the significance of DC-SIGN in primate lentiviral infections. 相似文献
956.
957.
Yanina Sguassero Cristina B. Cuesta Karen N. Roberts Elizabeth Hicks Daniel Comandé Agustín Ciapponi Sergio Sosa-Estani 《PloS one》2015,10(10)
Background
Chagas disease is caused by the flagellate protozoan Trypanosoma cruzi (T. cruzi). It is endemic in Latin American countries outside the Caribbean. The current criterion for cure in the chronic phase of the disease is the negativization of at least two serological tests such as enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IIF) and indirect hemagglutination assay (IHA). The serological evolution of treated subjects with chronic T. cruzi infection is variable. Treatment failure is indicated by a positive parasitological and/or molecular test (persistence of parasitemia).Objectives
To summarize the pattern of response to treatment of parasitological, molecular and serological tests performed during the follow-up of subjects with chronic T. cruzi infection.Methods
Electronic searches in relevant databases and screening of citations of potentially eligible articles were accomplished. Organizations focusing on neglected infectious diseases were asked for help in identifying relevant studies.Included studies were randomized controlled trials (RCTs), quasi-RCTs, and cohort studies involving adults and children with chronic infection who received trypanocidal treatment (benznidazole or nifurtimox) and were followed over time. The assessment of risk of bias was performed separately for each study design. The Cochrane Collaboration’s tool and the guidelines developed by Hayden et al. were used. Two reviewers extracted all data independently. A third review author was consulted in case of discordant opinion.Additional analyses were defined in ad-hoc basis. Scatter plots for percentage of positive parasitological and molecular tests and for negative serological tests were developed by using the lowess curve technique. Heterogeneity was measured by I2.The protocol was registered in PROSPERO, an international prospective register of systematic review protocols (Registration Number CRD42012002162).Results
Out of 2,136 citations screened, 54 studies (six RCTs and 48 cohort studies) were included. The smoothed curves for positive xenodiagnosis and positive polymerase chain reaction (PCR) were characterized by a sharp decrease at twelve month posttreatment. Afterwards, they reached 10–20% and 40% for xenodiagnosis and PCR, respectively. The smoothed curves for negative conventional serological tests increased up to 10% after 48 months of treatment. In the long-term, the rate of negativization was between 20% and 45%.The main sources of bias identified across cohort studies were the lack of control for confounding and attrition bias. In general, RCTs were judged as low risk of bias in all domains. The level of heterogeneity across included studies was moderate to high.Additional analysis were incomplete because of the limited availability of data. In this regard, the country of origin of study participants might affect the results of parasitological and molecular tests, while the level of risk of bias might affect serological outcomes. Subgroup analysis suggested that seronegativization occurs earlier in children compared to adults.Conclusions
We acknowledge that there is a dynamic pattern of response based on parasitological, molecular and serological tests in subjects chronically infected with T. cruzi after treatment. Our findings suggest a trypanocidal effect in the long-term follow-up.Further research is needed to explore potential sources of heterogeneity and to conduct reliable subgroup analysis. 相似文献958.
Davidova I Hicks MS Fedorak PM Suflita JM 《Journal of industrial microbiology & biotechnology》2001,27(2):80-86
Sulfide accumulation due to bacterial sulfate reduction is responsible for a number of serious problems in the oil industry.
Among the strategies to control the activity of sulfate-reducing bacteria (SRB) is the use of nitrate, which can exhibit a
variety of effects. We investigated the relevance of this approach to souring oil fields in Oklahoma and Alberta in which
water flooding is used to enhance oil recovery. SRB and nitrate-reducing bacteria (NRB) were enumerated in produced waters
from both oil fields. In the Oklahoma field, the rates of sulfate reduction ranged from 0.05 to 0.16 μM S day−1 at the wellheads, and an order of magnitude higher at the oil–water separator. Sulfide production was greatest in the water
storage tanks in the Alberta field. Microbial counts alone did not accurately reflect the potential for microbial activities.
The majority of the sulfide production appeared to occur after the oil was pumped aboveground, rather than in the reservoir.
Laboratory experiments showed that adding 5 and 10 mM nitrate to produced waters from the Oklahoma and Alberta oil fields,
respectively, decreased the sulfide content to negligible levels and increased the numbers of NRB. This work suggests that
sulfate reduction control measures can be concentrated on aboveground facilities, which will decrease the amount of sulfide
reinjected into reservoirs during the disposal of oil field production waters. Journal of Industrial Microbiology & Biotechnology (2001) 27, 80–86.
Received 30 January 2001/ Accepted in revised form 30 June 2001 相似文献
959.
Human immunodeficiency virus type 1 gp41 antibodies that mask membrane proximal region epitopes: antibody binding kinetics, induction, and potential for regulation in acute infection 总被引:2,自引:1,他引:2 下载免费PDF全文
Alam SM Scearce RM Parks RJ Plonk K Plonk SG Sutherland LL Gorny MK Zolla-Pazner S Vanleeuwen S Moody MA Xia SM Montefiori DC Tomaras GD Weinhold KJ Karim SA Hicks CB Liao HX Robinson J Shaw GM Haynes BF 《Journal of virology》2008,82(1):115-125
Two human monoclonal antibodies (MAbs) (2F5 and 4E10) against the human immunodeficiency virus type 1 (HIV-1) envelope g41 cluster II membrane proximal external region (MPER) broadly neutralize HIV-1 primary isolates. However, these antibody specificities are rare, are not induced by Env immunization or HIV-1 infection, and are polyspecific and also react with lipids such as cardiolipin or phosphatidylserine. To probe MPER anti-gp41 antibodies that are produced in HIV-1 infection, we have made two novel murine MAbs, 5A9 and 13H11, against HIV-1 gp41 envelope that partially cross-blocked 2F5 MAb binding to Env but did not neutralize HIV-1 primary isolates or bind host lipids. Competitive inhibition assays using labeled 13H11 MAb and HIV-1-positive patient plasma samples demonstrated that cluster II 13H11-blocking plasma antibodies were made in 83% of chronically HIV-1 infected patients and were acquired between 5 to 10 weeks after acute HIV-1 infection. Both the mouse 13H11 MAb and the three prototypic cluster II human MAbs (98-6, 126-6, and 167-D) blocked 2F5 binding to gp41 epitopes to variable degrees; the combination of 98-6 and 13H11 completely blocked 2F5 binding. These data provide support for the hypothesis that in some patients, B cells make nonneutralizing cluster II antibodies that may mask or otherwise down-modulate B-cell responses to immunogenic regions of gp41 that could be recognized by B cells capable of producing antibodies like 2F5. 相似文献
960.
High-performance liquid chromatography on a Zorbax NH2 analytical column, with acetonitrile: 0.05 m KH2PO4 (75:25, ) used as eluant, has allowed the separation, in less than 14 min, of ascorbic acid, erythorbic acid, dehydroascorbic acid, dehydroerythorbic acid, diketogulonic acid, and diketogluconic acid. Ultraviolet monitoring at 268 nm allows ascorbic acid and erythorbic acid to be detected at the 25-ng level, while refractive index detection monitors the elution of all six compounds. Tyrosine is a good internal standard, being well separated from the other compounds and having an adequate ultraviolet absorption at 268 nm. We have found dithiothreitol to be effective in rapidly reducing dehydroascorbic acid to ascorbic acid, providing the basis for indirectly determining dehydroascorbic acid after its reduction. The potential of this high-performance liquid chromatographic procedure for evaluating the levels of these compounds in orange juice and urine is demonstrated. 相似文献