48 research outputs found

    First Observation of a Spontaneously Matured Female European Eel (Anguilla anguilla)

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    This study reports on the first observation of a spontaneously matured female European eel. The 43-year-old eel, together with eleven other females, resided at an aquarium house since their capture in 2002 and stocking as glass eels in 1978. In June 2019, the girth of the belly of the female increased as a sign of oocyte maturation. The specimen had an estimated gonadosomatic index (GSI) of 47, only half of the oocytes were hydrated and matured, indicating that European eels are polycyclic batch spawners. The live eels of the cohort were still in the previtellogenic phase but their eye sizes were close to that of the matured eel. We hypothesize that substances released by other maturing and spawning fishes may have triggered puberty of the eel. This first observation, and the possibility of more eels maturing in the near future, provides a natural reference for the sexual maturation of the European eel.</p

    The variant rs77559646 associated with aggressive prostate cancer disrupts ANO7 mRNA splicing and protein expression

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    Prostate cancer is among the most common cancers in men, with a large fraction of the individual risk attributable to heritable factors. A majority of the diagnosed cases does not lead to a lethal disease, and hence biological markers that can distinguish between indolent and fatal forms of the disease are of great importance for guiding treatment decisions. Although over 300 genetic variants are known to be associated with prostate cancer risk, few have been associated with the risk of an aggressive disease. One such variant is rs77559646 located in ANO7. This variant has a dual function. It constitutes a missense mutation in the short isoform of ANO7 and a splice region mutation in full-length ANO7. In this study, we have analyzed the impact of the variant allele of rs77559646 on ANO7 mRNA splicing using a minigene splicing assay and by performing splicing analysis with the tools IRFinder (intron retention finder), rMATS (replicate multivariate analysis of transcript splicing) and LeafCutter on RNA sequencing data from prostate tissue of six rs77559646 variant allele carriers and 43 non-carriers. The results revealed a severe disruption of ANO7 mRNA splicing in rs77559646 variant allele carriers. Immunohistochemical analysis of prostate samples from patients homozygous for the rs77559646 variant allele demonstrated a loss of apically localized ANO7 protein. Our study is the first to provide a mechanistic explanation for the impact of a prostate cancer risk SNP on ANO7 protein production. Furthermore, the rs77559646 variant is the first known germline loss-of-function mutation described for ANO7. We suggest that loss of ANO7 contributes to prostate cancer progression.</p

    Polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in fish from the Netherlands: concentrations, profiles and comparison with DR CALUX® bioassay results

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    Fish from Dutch markets were analysed for concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) and compared with the new European maximum residue levels (MRLs), set in 2006. In a first study on 11 different fish and shellfish from various locations, concentrations of PCDD/Fs were nearly all below the MRL for PCDD/Fs [4 pg toxic equivalents (TEQ) per gram wet weight (ww)] and nearly all below 8 pg total TEQ/g ww, the new MRL for the sum of PCDD/Fs and DL-PCBs. Some samples exceeded the total TEQ MRL, such as anchovy, tuna and sea bass. Furthermore, 20 (out of 39) wild eel samples exceeded the specific MRL for eel (12 pg total TEQ/g ww), as the study revealed PCDD/F TEQ levels of 0.2-7.9 pg TEQ/g ww and total TEQ values of 0.9 to 52 pg/g ww. TEQ levels in farmed and imported eel were lower and complied with the MRLs. Smoking eel, a popular tradition in the Netherlands, only had marginal effects on PCDD/F and DL-PCB concentrations. Owing to volatilization, concentrations of lower-chlorinated PCBs were reduced to below the limit of quantification after smoking. DL-PCBs contributed 61-97% to the total TEQ in all eel samples. This also holds for other fish and shellfish (except shrimps): DL-PCB contributed (on average) from 53 (herring) to 83% (tuna) to the total TEQ. Principal-component analysis revealed distinctive congener profiles for PCDD/Fs and non-ortho PCBs for mussels, pikeperch, herring and various Mediterranean fish. The application of new TCDD toxic equivalency factors (TEFs) set by the World Health Organization in 2006 (to replace the 1997 TEFs) resulted in lower TEQ values, mainly owing to a decreased mono-ortho PCB contribution. This decrease is most pronounced for eel, owing to the relative high mono-ortho PCB concentrations in eel. Consequently, a larger number of samples would comply with the MRLs when the new TEFs are applied. The DR CALUX (R) assay may be used for screening total TEQ levels in eel, in combination with gas chromatography-high resolution mass spectrometry confirmation of suspected samples. An almost 1:1 correlation was found when the 1997 TEFs were applied, but, surprisingly, a 1.4-fold overestimation occurred with application of the 2006 TEFs

    Shelter and depth use of adult noble crayfish (Astacus astacus (L.)) and signal crayfish (Pacifastacus leniusculus (Dana)) in the presence of a predator.

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    Freshwater Crayfish -sarjaa ei löydy tietokannoista (ei ole web of science:ssäkään), siksi ei ole ISSN -numeroa eikä muita sarjan tietoja

    The effects of minimum size regulations and exploitation on population dynamics of the noble crayfish (Astacus astacus (Linnaeus)) in a small lake in central Finland: A seven year study.

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    Freshwater Crayfish -sarjaa ei löydy tietokannoista ja siksi ei ole ISSN -numeroa ja muita toetoj

    High Nitrogen Removal in a Constructed Wetland Receiving Treated Wastewater in a Cold Climate

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    Constructed wetlands provide cost-efficient nutrient removal, with minimal input of human labor and energy, and their number is globally increasing. However, in northern latitudes, wetlands are rarely utilized, because their nutrient removal efficiency has been questioned due to the cold climate. Here, we studied nutrient retention and nitrogen removal in a boreal constructed wetland (4-ha) receiving treated nitrogen-rich wastewater. On a yearly basis, most of the inorganic nutrients were retained by the wetland. The highest retention efficiency was found during the ice-free period, being 79% for ammonium-nitrogen (NH4+-N), 71% for nitrate-nitrogen (NO3--N), and 88% for phosphate-phosphorus (PO43--P). Wetland also acted as a buffer zone during the disturbed nitrification process of the wastewater treatment plant. Denitrification varied between 106 and 252 mg N m(-2) d(-1) during the ice-free period. During the ice-cover period, total gaseous nitrogen removal was 147 mg N m(-2) d(-1) from which 66% was removed as N-2, 28.5% as N2O through denitrification, and 5.5% as N-2 through anammox. Nearly 2600 kg N y(-1) was estimated to be removed through microbial gaseous N-production which equaled 72% of NO3--N and 60% of TN yearly retention in the wetland. The wetland retained nutrients even in winter, when good oxygen conditions prevailed under ice. The results suggest that constructed wetlands are an efficient option for wastewater nitrogen removal and nutrient retention also in cold climates.Peer reviewe

    Effect of ageing on the mechanical properties of cold formed S700 rectangular hollow

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    Abstract The aim of this work is to study the effect of ageing (250 °C for 1 h) on the mechanical properties of the cold formed S700 rectangular hollow section. The investigated hot rolled steel strip was produced thermomechanical rolling followed by direct quenching. The dimension of the investigated hollow section was 120 x 120 x 10 mm and the corner radii and the other tolerances compliant with EN 10219. Tensile properties and Charpy-V impact toughness were determined for the base material and flat and corner area of the hollow section. The results showed that the tensile strength in the corner was slightly higher in comparison with the flat side, revealing higher cold deformation rate in the corner. Ageing increased the strength level relatively higher than cold forming without losing any elongation properties. The impact energies were at the high level at −40°C and −60°C in cold formed and aged materials. Even at −80°C, the CV results were 118 J/cm². It is also notable that no difference in CV values between the flat and the corner samples were observed. Thus, the results showed that the flat side specimens testing provides sufficient information of mechanical properties of the cold formed rectangular hollow sections and no need demanding corner sample testing when the structural hollow section is produced by using the thermomechanical controlled and direct-quenched base material. Furthermore, results showed that cold formed S700 is excellent for offshore steels, as steels are used even colder conditions as before

    Effect of direct quenching on the mechanical properties of cold formed S500 rectangular hollow section

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    Abstract The aim of this work is to study the effect of cold forming on the mechanical properties and microstructure of a steel grades used in manufacturing of rectangular hollow sections. Conventional and a direct-quenched steel sections in 500 MPa strength level are compared. Tensile properties and Charpy-V impact toughness were determined for the flat side and corner of hollow section. The results show that the strength in corner area is approximately 50 MPa higher and the elongation at fracture 4 % lower compared to flat side area, revealing the work hardening and the effect of higher cold deformation rate in corner areas. The impact energies of sub-sized samples (5 mm x 10 mm x 55 mm) were at high level at -40 °C and -60 °C in both steels. However, the direct-quenched steel had improved impact toughness when testing temperature decreased. It is also notable that no differences in CV values between the flat and corner samples were observed. EBSD results showed compressed microstructure in inner corner radius and the outer was stretched in correspondingly. This resulted inner corner area having the smallest grain sizes. Additionally, a brief discussion between the mechanical properties of structural rectangular hollow sections is presented

    FLD Assessment Using the Proposed New Standard

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    Texture evolution during cold forming of rectangular hollow section

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    Abstract This work aims to study the effect of cold forming on the texture evolution during the manufacturing of rectangular hollow sections. Conventional TMCP steel and a direct-quenched steel in 420 MPa strength level are compared. The texture was characterized at the centerline (S=0) and both surfaces (S=0.8) for base material, four flat side and one corner samples of the rectangular hollow section. The results show that the flat sides of both steels have the minor intensity of ~{554}&lt;225&gt; and ~{112}&lt;110&gt; texture components and an intense texture component of ~{001}&lt;110&gt; in the centerline. Generally, any significant difference between four flat size samples was not found and texture intensities of the conventional TMCP steel were slightly sharper compared to direct-quenched steel. The most important change is observed with the inner corner samples, where the randomly oriented texture in the base material and flat side samples changes to the {110}&lt;111&gt;/&lt;112&gt;> shear texture components
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