130 research outputs found

    Nitrogen source-dependent inhibition of yeast growth by glycine and its N-methylated derivatives

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    The effect of nitrogen source on the inhibitory properties of glycine and its N-methylated derivatives N-methylglycine (sarcosine), N,N-dimethylglycine, N,N,N-trimethylglycine (glycine betaine) on yeast growth was investigated. On solid minimal medium, all four glycine species completely or partially inhibited growth of Kluyveromyces lactis, Komagataella pastoris, Ogataea arabinofermentans, Spathaspora passalidarum and Yamadazyma tenuis at concentrations 5-10 mM when 10 mM NH4Cl was the sole source of nitrogen. If NH4Cl was substituted by sodium L-glutamate as the sole source of nitrogen, obvious growth inhibition by glycine and its N-methylated derivatives was generally not observed in any of these species. No obvious growth inhibition by any of the glycine species at a concentration of 10 mM was observed in Cyberlindnera jadinii, Lipomyces starkeyi, Lodderomyces elongisporus, Scheffersomyces stipitis or Yarrowia lipolytica on solid minimal medium irrespective of whether the nitrogen source was NH4Cl or sodium L-glutamate. Growth inhibition assays of K. pastoris in liquid minimal medium supplemented with increasing concentrations of N,N-dimethylglycine demonstrated inhibitory effects for nine tested nitrogen sources. In most cases, N,N-dimethylglycine supplementation caused a decrease in growth efficiency that appeared to be proportional to the concentration of N,N-dimethylglycine. The biological relevance of these results is discussed

    Fulfilling the Promises of Fermentation-Derived Foods

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    Fermentation-derived foods (FDFs) such as cultured animal cells, edible microbial biomass, and recombinant food proteins have recently seen a notable surge in both investment and public interest. FDFs have been promoted as a more ethical, resilient, and environmentally sustainable food alternative to animal-derived foods such as meat, eggs, and dairy. However, some of the manufacturing process choices and sociopolitical assumptions made by actors in this space could risk undermining the goals of the technology as stated above. This article highlights five aspects of FDFs that should be carefully considered if they are to assist human society successfully transition to a more ethical, sustainable, and resilient food production system: (1) sustainable nitrogen fixation and management, (2) transitioning away from sugar feedstocks, (3) realistic expectations of consumer adoption rate, (4) careful consideration of the role of intellectual property, and (5) greater emphasis on food products that do not require cold or frozen storage

    Combined physical and statistical modeling of laser induced ultrasound signals from thin light absorbing films

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    This paper presents a method for predicting the ultrasound pulses generated by thin semi-transparent polymer films, excited by a short laser pulse. The acoustic pressure is first modeled based on the physical properties of the polymer. Partial Least-Squares Regression is then used to link the model pressure to the ultrasound pulses measured by an ultrasound transducer. The uncertainty of the regression is also simulated, showing that the method is robust to noise in the measurementsGodkänd; 2013; 20130611 (johanc

    Components explain, but do eddy fluxes constrain? Carbon budget of a nitrogen-fertilized boreal Scots pine forest

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    Nitrogen (N) fertilization increases biomass and soil organic carbon (SOC) accumulation in boreal pine forests, but the underlying mechanisms remain uncertain. At two Scots pine sites, one undergoing annual N fertilization and the other a reference, we sought to explain these responses.We measured component fluxes, including biomass production, SOC accumulation, and respiration, and summed them into carbon budgets. We compared the resulting summations to ecosystem fluxes measured by eddy covariance.N fertilization increased most component fluxes (P −2 yr−1. Stemwood production increases were ascribed to this partitioning shift, gross primary production (GPP), and carbon-use efficiency, in that order. The methods agreed in their estimates of GPP in both stands (P > 0.05), but the components detected an increase in net ecosystem production (NEP) (190 (54) g C m−2 yr−1; P −2 yr−1; ns).The pairing of plots, the simplicity of the sites, and the strength of response provide a compelling description of N effects on the C budget. However, the disagreement between methods calls for further paired tests of N fertilization effects in simple forest ecosystems

    Impairment of Sexual Life in 3,485 Dermatological Outpatients From a Multicentre Study in 13 European Countries

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    Skin conditions may have a strong impact on patients' sexual life, and thus influence personal relationships. Sexual issues are difficult to discuss directly in clinical practice, and a mediated instrument may be useful to capture such information. In this study item 9 of the Dermatology Life Quality Index was used to collect information on sexual impact of several skin conditions in 13 European countries. Among 3,485 patients, 23.1% reported sexual problems. The impairment was particularly high in patients with hidradenitis suppurativa, prurigo, blistering disorders, psoriasis, urticaria, eczema, infections of the skin, or pruritus. Sexual impact was strongly associated with depression, anxiety, and suicidal ideation. It was generally more frequent in younger patients and was positively correlated with clinical severity and itch. It is important to address the issue of sexual well-being in the evaluation of patients with skin conditions, since it is often linked to anxiety, depression, and even suicidal ideation.Peer reviewedFinal Published versio

    MT1-MMP and ADAM10/17 exhibit a remarkable overlap of shedding properties

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    Membrane-type-I matrix metalloproteinase (MT1-MMP) is one of six human membrane-bound MMPs and is responsible for extracellular matrix remodelling by degrading several substrates like fibrillar collagens, including types I-III, or fibronectin. Moreover, MT1-MMP was described as a key player in cancer progression and it is involved in various inflammatory processes, as well as in the pathogenesis of Alzheimer's disease (AD). The membrane-tethered metalloprotease meprin β as well as a disintegrin and metalloproteinase 10 (ADAM10) and ADAM17 are also associated with these diseases. Interestingly, meprin β, ADAM10/17 and MT1-MMP also have a shared substrate pool including the interleukin-6 receptor and the amyloid precursor protein. We investigated the interaction of these proteases, focusing on a possible connection between MT1-MMP and meprin β, to elucidate the potential mutual regulations of both enzymes. Herein, we show that besides ADAM10/17, MT1-MMP is also able to shed meprin β from the plasma membrane, leading to the release of soluble meprin β. Mass spectrometry-based cleavage site analysis revealed that the cleavage of meprin β by all three proteases occurs between Pro602 and Ser603 , N-terminal of the EGF-like domain. Furthermore, only inactive human pro-meprin β is shed by MT1-MMP, which is again in accordance with the shedding capability observed for ADAM10/17. Vice versa, meprin β also appears to shed MT1-MMP, indicating a complex regulatory network. Further studies will elucidate this well-orchestrated proteolytic web under distinct conditions in health and disease and will possibly show whether the loss of one of the above-mentioned sheddases can be compensated by the other enzymes

    Long-term nitrogen addition raises the annual carbon sink of a boreal forest to a new steady-state

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    The boreal forest is an important global carbon (C) sink. Since low soil nitrogen (N) availability is commonly a key constraint on forest productivity, the prevalent view is that increased N input enhances its C sink-strength. This understanding however relies primarily on observations of increased aboveground tree biomass and soil C stock following N fertilization, whereas empirical data evaluating the effects on the whole ecosystem-scale C balance are lacking. Here we use a unique long-term experiment consisting of paired forest stands with eddy covariance measurements to explore the effect of ecosystem-scale N fertilization on the C balance of a managed boreal pine forest. We find that the annual C uptake (i.e. net ecosystem production, NEP) at the fertilized stand was 16 +/- 2% greater relative to the control stand by the end of the first decade of N addition. Subsequently, the ratio of NEP between the fertilized and control stand remained at a stable level during the following five years with an average NEP to N response of 7 & PLUSMN; 1 g C per g N. Our study reveals that this non-linear response of NEP to long-term N fertilization was the result of a cross-seasonal feedback between the N-induced increases in both growing-season C uptake and subsequent winter C emission. We further find that one decade of N addition altered the sensitivity of ecosystem C fluxes to key environmental drivers resulting in divergent responses to weather patterns. Thus, our study highlights the need to account for ecosystem-scale responses to perturbations to improve our understanding of nitrogen-carbon-climate feedbacks in boreal forests.Peer reviewe

    Long-term nitrogen addition raises the annual carbon sink of a boreal forest to a new steady-state

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    The boreal forest is an important global carbon (C) sink. Since low soil nitrogen (N) availability is commonly a key constraint on forest productivity, the prevalent view is that increased N input enhances its C sink-strength. This understanding however relies primarily on observations of increased aboveground tree biomass and soil C stock following N fertilization, whereas empirical data evaluating the effects on the whole ecosystem-scale C balance are lacking. Here we use a unique long-term experiment consisting of paired forest stands with eddy covariance measurements to explore the effect of ecosystem-scale N fertilization on the C balance of a managed boreal pine forest. We find that the annual C uptake (i.e. net ecosystem production, NEP) at the fertilized stand was 16 +/- 2% greater relative to the control stand by the end of the first decade of N addition. Subsequently, the ratio of NEP between the fertilized and control stand remained at a stable level during the following five years with an average NEP to N response of 7 & PLUSMN; 1 g C per g N. Our study reveals that this non-linear response of NEP to long-term N fertilization was the result of a cross-seasonal feedback between the N-induced increases in both growing-season C uptake and subsequent winter C emission. We further find that one decade of N addition altered the sensitivity of ecosystem C fluxes to key environmental drivers resulting in divergent responses to weather patterns. Thus, our study highlights the need to account for ecosystem-scale responses to perturbations to improve our understanding of nitrogen-carbon-climate feedbacks in boreal forests.Peer reviewe

    Two conserved modules of Schizosaccharomyces pombe Mediator regulate distinct cellular pathways

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    Mediator is an evolutionary conserved coregulator complex required for transcription of almost all RNA polymerase II-dependent genes. The Schizosaccharomyces pombe Mediator consists of two dissociable components—a core complex organized into a head and middle domain as well as the Cdk8 regulatory subcomplex. In this work we describe a functional characterization of the S. pombe Mediator. We report the identification of the S. pombe Med20 head subunit and the isolation of ts alleles of the core head subunit encoding med17+. Biochemical analysis of med8ts, med17ts, Δmed18, Δmed20 and Δmed27 alleles revealed a stepwise head domain molecular architecture. Phenotypical analysis of Cdk8 and head module alleles including expression profiling classified the Mediator mutant alleles into one of two groups. Cdk8 module mutants flocculate due to overexpression of adhesive cell-surface proteins. Head domain-associated mutants display a hyphal growth phenotype due to defective expression of factors required for cell separation regulated by transcription factor Ace2. Comparison with Saccharomyces cerevisiae Mediator expression data reveals that these functionally distinct modules are conserved between S. pombe and S. cerevisiae

    The psychological burden of skin diseases: a cross-sectional multicenter study among dermatological out-patients in 13 European countries.

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    The contribution of psychological disorders to the burden of skin disease has been poorly explored, and this is a large-scale study to ascertain the association between depression, anxiety, and suicidal ideation with various dermatological diagnoses. This international multicenter observational cross-sectional study was conducted in 13 European countries. In each dermatology clinic, 250 consecutive adult out-patients were recruited to complete a questionnaire, reporting socio-demographic information, negative life events, and suicidal ideation; depression and anxiety were assessed with the Hospital Anxiety and Depression Scale. A clinical examination was performed. A control group was recruited among hospital employees. There were 4,994 participants--3,635 patients and 1,359 controls. Clinical depression was present in 10.1% patients (controls 4.3%, odds ratio (OR) 2.40 (1.67-3.47)). Clinical anxiety was present in 17.2% (controls 11.1%, OR 2.18 (1.68-2.82)). Suicidal ideation was reported by 12.7% of all patients (controls 8.3%, OR 1.94 (1.33-2.82)). For individual diagnoses, only patients with psoriasis had significant association with suicidal ideation. The association with depression and anxiety was highest for patients with psoriasis, atopic dermatitis, hand eczema, and leg ulcers. These results identify a major additional burden of skin disease and have important clinical implications.Peer reviewedFinal Published versio
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