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91.
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Corn samples were collected in 1999 from three departments of Entre Réos province, Argentina, and were surveyed for mould contamination and natural occurrence ofFusarium mycotoxins, ochratoxin A and aflatoxins.Fusarium verticillioides was the most prevalent fungal species recorded at all departments. Zearalenone, deoxynivalenol and ochratoxin A were not found in any samples. Only one of the 52 corn samples analysed was contaminated with aflatoxin B1 (17 μg/kg). Fumonisin B1 was found in 58 % of samples (range of positive samples: 47– 3,347 μg/kg), fumonisin B2 in 33.0 % (range of positive samples: 23–537 μg/kg) and fumonisin B3 in 25.0 % (range of positive samples: 24–287 μg/kg) of them. This is the first report on the natural occurrence of mycotoxins in corn from Entre Ríos province, Argentina. Levels of fumonisins were lower than detected in other Argentinian provinces.  相似文献   
93.
One of the earliest manifestations of anteroposterior pattering in the developing brain is the restricted expression of Six3 and Irx3 in the anterior and posterior forebrain, respectively. Consistent with the role of Wnts as posteriorizing agents in neural tissue, we found that Wnt signaling was sufficient to induce Irx3 and repress Six3 expression in forebrain explants. The position of the zona limitans intrathalamica (zli), a boundary-cell population that develops between the ventral (vT) and dorsal thalamus (dT), is predicted by the apposition of Six3 and Irx3 expression domains. The expression patterns of several inductive molecules are limited by the zli, including Wnt3, which is expressed posterior to the zli in the dT. Wnt3 and Wnt3a were sufficient to induce the dT marker Gbx2 exclusively in explants isolated posterior to the presumptive zli. Blocking the Wnt response allowed the induction of the vT-specific marker Dlx2 in prospective dT tissue. Misexpression of Six3 in the dT induced Dlx2 expression and inhibited the expression of both Gbx2 and Wnt3. These results demonstrate a dual role for Wnt signaling in forebrain development. First, Wnts directed the initial expression of Irx3 and repression of Six3 in the forebrain, delineating posterior and anterior forebrain domains. Later, continued Wnt signaling resulted in the induction of dT specific markers, but only in tissues that expressed Irx3.  相似文献   
94.
INTRODUCTION: The molecular mechanisms underlying aggressive versus indolent disease are not fully understood. Recent research has implicated a class of molecules known as long noncoding RNAs (lncRNAs) in tumorigenesis and progression of cancer. Our objective was to discover lncRNAs that differentiate aggressive and indolent prostate cancers. METHODS: We analyzed paired tumor and normal tissues from six aggressive Gleason score (GS) 8-10 and six indolent GS 6 prostate cancers. Extracted RNA was split for poly(A)+ and ribosomal RNA depletion library preparations, followed byRNA sequencing (RNA-Seq) using an Illumina HiSeq 2000. We developed an RNA-Seq data analysis pipeline to discover and quantify these molecules. Candidate lncRNAs were validated using RT-qPCR on 87 tumor tissue samples: 28 (GS 6), 28 (GS 3+4), 6 (GS 4+3), and 25 (GS 8-10). Statistical correlations between lncRNAs and clinicopathologic variables were tested using ANOVA. RESULTS: The 43 differentially expressed (DE) lncRNAs between aggressive and indolent prostate cancers included 12 annotated and 31 novel lncRNAs. The top six DE lncRNAs were selected based on large, consistent fold-changes in the RNA-Seq results. Three of these candidates passed RT-qPCR validation, including AC009014.3 (P < .001 in tumor tissue) and a newly discovered X-linked lncRNA named XPLAID (P = .049 in tumor tissue and P = .048 in normal tissue). XPLAID and AC009014.3 show promise as prognostic biomarkers. CONCLUSIONS: We discovered several dozen lncRNAs that distinguish aggressive and indolent prostate cancers, of which four were validated using RT-qPCR. The investigation into their biology is ongoing.  相似文献   
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The number of breeding common sandpipers has declined in Britain due to poorer return rates from non‐breeding areas. To investigate little known aspects of their annual cycle, breeding common sandpipers were fitted with geolocators to track their migrations and determine their non‐breeding areas. Ten tagged birds left Scotland on 9 July (median dates and durations are given throughout the abstract). Short‐term staging was carried out by some birds in England and Ireland, then for longer by most birds in Iberia before continuing to West Africa, arriving on 28 July. Six birds spent most of the non‐breeding season (October–February) on the coast of Guinea‐Bissau, suggesting that this is a key area. Single birds occurred in Sierra Leone, Guinea, the Canary Islands and western Sahara. The southward migration from Scotland took 17.5 d (range 1.5–24 d), excluding the initial fuelling period. The first northward movement from Africa was on 12 April. Staging occurred in either Morocco, Iberia or France. Arrival in Scotland was on 2 May. The northward migration took 16 d (range 13.5–20.5 d). The main migration strategy involved short‐ and medium‐range flights, using tail‐winds in most cases. Variation in strategy was associated with departure date; birds that left later staged for shorter durations. Coastal West Africa provides two major habitats for common sandpipers: mudflats associated with mangroves and rice fields. Although the area of mangrove has been depleted, the scale of loss has probably been insufficient to account for the decline in sandpiper numbers. Rice fields are expanding, providing feeding areas for water‐birds. Meteorological data during the migrations suggest that the weather during the southward migration is unlikely to contribute to a population decline but strong cross‐winds or head‐winds during the northward migration to the breeding grounds may do so.  相似文献   
97.
Partial denaturation mapping, restriction endonuclease digestion, and electron microscopy were used to determine which end of the linear duplex replicative-form (RF) DNA molecule contains the origin of RF replication for the parvovirus H-1. This origin was localized within approximately 300 base pairs of the arbitrarily designated right end of the RF DNA, in the EcoRI or HaeII-A fragment. Based on denaturation behavior in formamide, the right end was also found to have a relatively high guanine plus cytosine content, whereas the region adjacent to the left terminus of the RF DNA molecule was adenine plus thymine rich.  相似文献   
98.
Expressions for the probability and average time of detection of a recessive visible gene in populations where there is partial selfing or partial full-sib mating are presented. A small increase in the proportion of inbred matings greatly reduces the average time until detection and increases the proportion detected. Unless the proportion of inbred matings or the population size is very small, the time and proportion detected are approximately independent of the population size.  相似文献   
99.
An extensive monitoring and survey program in Mississippi was conducted from 2000 to 2004 to investigate the distribution of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). Seventy-two towns from 22 counties in southern Mississippi were monitored with a total of 3914 traps that catch alates during the swarming season. In addition, 259 licensed pest management professionals in Mississippi were surveyed to determine the locations of termite infestations treated. The alates of C. formosanus were recovered in 12 counties with light traps, and termite infestations were documented in an additional 13 from data collected in the termite survey. Infestations of C. formosanus have been documented in urban, urban cluster, rural, and forested areas of Mississippi. However, the distribution in mean total capture of alates for 4 yr differed significantly among the four ecological areas with the highest percentage in forested areas (31%) and the lowest percentage in urban cluster areas (17%). Most of the infestations of C. formosanus were geographically distributed along the coastal areas of southern Mississippi from Gulfport to Pascagoula. The greatest total number of alates captured in light traps was documented in Pearl River County. Mass swarming of C. formosanus occurred primarily in May or June, depending on weather conditions. The number of documented counties with the evidence of large and widely dispersed swarms of C. formosanus in different ecological areas, and the increase in total annual alate captures from 2000 to 2003, suggest that this invasive termite species is now firmly established in Mississippi.  相似文献   
100.

Background

Overcoming spaceflight-induced (patho)physiologic adaptations is a major challenge preventing long-term deep space exploration. RNA interference (RNAi) has emerged as a promising therapeutic for combating diseases on Earth; however the efficacy of RNAi in space is currently unknown.

Methods

Caenorhabditis elegans were prepared in liquid media on Earth using standard techniques and treated acutely with RNAi or a vector control upon arrival in Low Earth Orbit. After culturing during 4 and 8 d spaceflight, experiments were stopped by freezing at −80°C until analysis by mRNA and microRNA array chips, microscopy and Western blot on return to Earth. Ground controls (GC) on Earth were simultaneously grown under identical conditions.

Results

After 8 d spaceflight, mRNA expression levels of components of the RNAi machinery were not different from that in GC (e.g., Dicer, Argonaute, Piwi; P>0.05). The expression of 228 microRNAs, of the 232 analysed, were also unaffected during 4 and 8 d spaceflight (P>0.05). In spaceflight, RNAi against green fluorescent protein (gfp) reduced chromosomal gfp expression in gonad tissue, which was not different from GC. RNAi against rbx-1 also induced abnormal chromosome segregation in the gonad during spaceflight as on Earth. Finally, culture in RNAi against lysosomal cathepsins prevented degradation of the muscle-specific α-actin protein in both spaceflight and GC conditions.

Conclusions

Treatment with RNAi works as effectively in the space environment as on Earth within multiple tissues, suggesting RNAi may provide an effective tool for combating spaceflight-induced pathologies aboard future long-duration space missions. Furthermore, this is the first demonstration that RNAi can be utilised to block muscle protein degradation, both on Earth and in space.  相似文献   
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