Browsing by Subject "ACCUMULATION"

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  • Vihma, Veera; Heinonen, Sini; Naukkarinen, Jussi; Kaprio, Jaakko; Rissanen, Aila; Turpeinen, Ursula; Hämäläinen, Esa; Hakkarainen, Antti; Lundbom, Jesper; Lundbom, Nina; Mikkola, Tomi S.; Tikkanen, Matti J.; Pietiläinen, Kirsi H. (2018)
    Objective: Obesity may alter serum steroid concentrations and metabolism. We investigated this in healthy young women with increased body fat and their leaner co-twin sisters. Design: Age and genetic background both strongly influence serum steroid levels and body composition. This is a cross-sectional study of 13 female monozygotic twin pairs (age, 23-36 years), ten of which were discordant for body mass index (median difference in body weight between the co-twins, 19 kg). Methods: We determined body composition by dual energy X-ray absorptiometry and magnetic resonance imaging, serum androgens by liquid chromatography-tandem mass spectrometry, and mRNA expression of genes in subcutaneous adipose tissue and adipocytes. Results: The heavier women had lower serum dehydroepiandrosterone (DHEA), dihydrotestosterone (DHT), and sex hormone-binding globulin (SHBG) (P <0.05 for all) compared to their leaner co-twins with no differences in serum testosterone or androstenedione levels. Serum DHEA correlated inversely with %body fat (r = -0.905, P = 0.002), and DHT positively with SHBG (r = 0.842, P = 0.002). In adipose tissue or adipocytes, expressions of STS (steroid sulfatase) and androgen-related genes were significantly higher in the heavier compared to the leaner co-twin, and within pairs, correlated positively with adiposity but were not related to serum androgen levels. None of the serum androgen or SHBG levels correlated with indices of insulin resistance. Conclusions: Serum DHEA levels were best predicted by %body fat, and serum DHT by SHBG. These or other serum androgen concentrations did not reflect differences in androgen-related genes in adipose tissue. General or intra-abdominal adiposity were not associated with increased androgenicity in young women.
  • Tossavainen, Marika; Ilyass, Usman; Ollilainen, Velimatti; Valkonen, Kalle; Ojala, Anne; Romantschuk, Martin (2019)
    Nitrogen limitation is considered a good strategy for enhancement of algal lipid production while conversely N repletion has been shown to result in biomass rich in proteins. In this study, the influence of long-term N limitation on Euglena gracilis fatty acid (FA), protein, chlorophyll a, and carotenoid concentrations was studied in N limited cultures. Biomass composition was analyzed from three-time points from N starved late stationary phase cultures, exposed to three different initial N concentrations in the growth medium. Total lipid content increased under N limitation in ageing cultures, but the low N content and prolonged cultivation time resulted in the formation of a high proportion of saturated FAs. Furthermore, growth as well as the production of proteins, chlorophyll a and carotenoids were enhanced in higher N concentrations and metabolism of these cellular components stayed stable during the stationary growth phase. Our findings showed that a higher N availability and a shorter cultivation time is a good strategy for efficient E. gracilis biomass production, regardless of whether the produced biomass is intended for maximal recovery of polyunsaturated FAs, proteins, or photosynthetic pigments. Additionally, we showed an increase of neoxanthin, beta-carotene, and diadinoxanthin as a response to higher N availability.
  • Medina, Tuula Penate; Gerle, Mirko; Humbert, Jana; Chu, Hanwen; Koepnick, Anna-Lena; Barkmann, Reinhard; Garamus, Vasil M.; Sanz, Beatriz; Purcz, Nicolai; Will, Olga; Appold, Lia; Damm, Timo; Suojanen, Juho; Arnold, Philipp; Lucius, Ralph; Willumeit-Roemer, Regina; Acil, Yahya; Wiltfang, Joerg; Goya, Gerardo F.; Glueer, Claus C.; Medina, Oula Penate (2020)
    Simple Summary A novel active release system magnetic sphingomyelin-containing liposome encapsulated with indocyanine green, fluorescent marker, or the anticancer drug cisplatin was evaluated. The liposomal sphingomyelin is a target for the sphingomyelinase enzyme, which is released by stressed cells. Thus, sphingomyelin containing liposomes behave as a sensitizer for biological stress situations. In addition, the liposomes were engineered by adding paramagnetic beads to act as a receiver of outside given magnetic energy. The enzymatic activity towards liposomes and destruction caused by the applied magnetic field caused the release of the content from the liposomes. By using these novel liposomes, we could improve the drug release feature of liposomes. The improved targeting and drug-release were shown in vitro and the orthotopic tongue cancer model in mice optical imaging. The increased delivery of cisplatin prolonged the survival of the targeted delivery group versus free cisplatin. Most available cancer chemotherapies are based on systemically administered small organic molecules, and only a tiny fraction of the drug reaches the disease site. The approach causes significant side effects and limits the outcome of the therapy. Targeted drug delivery provides an alternative to improve the situation. However, due to the poor release characteristics of the delivery systems, limitations remain. This report presents a new approach to address the challenges using two fundamentally different mechanisms to trigger the release from the liposomal carrier. We use an endogenous disease marker, an enzyme, combined with an externally applied magnetic field, to open the delivery system at the correct time only in the disease site. This site-activated release system is a novel two-switch nanomachine that can be regulated by a cell stress-induced enzyme at the cellular level and be remotely controlled using an applied magnetic field. We tested the concept using sphingomyelin-containing liposomes encapsulated with indocyanine green, fluorescent marker, or the anticancer drug cisplatin. We engineered the liposomes by adding paramagnetic beads to act as a receiver of outside magnetic energy. The developed multifunctional liposomes were characterized in vitro in leakage studies and cell internalization studies. The release system was further studied in vivo in imaging and therapy trials using a squamous cell carcinoma tumor in the mouse as a disease model. In vitro studies showed an increased release of loaded material when stress-related enzyme and magnetic field was applied to the carrier liposomes. The theranostic liposomes were found in tumors, and the improved therapeutic effect was shown in the survival studies.
  • Wasiljeff, Joonas; Kaakinen, Anu; Salminen, Johanna; Zhang, Zhaoqun (2020)
    The transition from Eocene to Oligocene and its implications in the terrestrial realm has been a focal target for Cenozoic climate and environment research as it is widely considered the most dramatic climatic shift of the past 50 million years. Tibetan Plateau and proximal areas have been of utmost interest since the biogeographic relationships and understanding of the depositional environments in the region have remained unsettled during and after the Eocene-Oligocene transition (EOT). This study derives a first chronostratigraphic framework for Ulantatal, a fossiliferous area in Inner Mongolia, China. Based on paleomagnetic reversal stratigraphy and the constraints of faunal correlations, the time spanned in the strata is between ca. 35 and 27 Ma, thus exposing a long sedimentary succession ranging from the latest Eocene to late Oligocene. The lithological characteristics reveal these extensive fine-grained sediments mainly originate from eolian dust deposition, the onset of which is constrained at the latest Eocene (ca. 34.8 Ma). The presence of post "Mongolian Remodeling" fauna already in the late Eocene of Ulantatal demonstrates unequivocally that the major faunal turnover preceded the Eocene-Oligocene boundary, earlier to what has been recorded from other East Asian localities. The faunal composition predominated by rodents and lagomorphs remains strikingly stable across the Eocene-Oligocene boundary, suggesting the EOT related change in the animal communities was gradual or stepwise rather than abrupt. Moreover, the turnover into this environment dominated by small mammals can be linked with Eocene acidification of Asia, highlighting the dynamic responses of terrestrial systems to changing environment and climate associated with the EOT. (C) 2020 The Author(s). Published by Elsevier B.V.
  • Gautam, Mukesh Kumar; Lee, Kwang-Sik; Berg, Bjorn; Song, Byeong-Yeol (2020)
    Evaluating the decomposition-based change dynamics of various elements in plant litter is important for improving our understanding about their biogeochemical cycling in ecosystems. We have studied the concentrations of major, trace, and rare earth elements (REEs) (34 elements) in green tissue litter, and soil and their dynamics in the decomposing litters of successional annual fleabane (Erigeron annuus) and silvergrass (Miscanthus sinensis). Concentrations of major and trace elements in the litter of annual fleabane were 1.02-2.71 times higher compared to silvergrass. For REEs the difference between the two litter types for elements studied was in the range of 1.02-1.29 times. Both the litters showed a general decrease in the concentrations of elements in the initial stages of decomposition (60-90 days). All the major and trace elements (except for Na) in silvergrass showed a net increase in concentration at the end of the decomposition study (48.9-52.5% accumulated mass loss). Contrastingly, a few trace elements (Mn, Mo, Sr, Zn, Sb, and Cd) in annual fleabane showed a net decrease in their concentrations. For REEs, there was an increase in concentrations as well as in net amounts in both litter types. Similarities observed in the dynamics together with high and significant correlations among them likely suggest their common source. The higher concentrations of REEs in soil likely suggest its role in the net increase in REEs' concentrations and amount in litter during decomposition. (C) 2020 Elsevier B.V. All rights reserved.
  • Chen, Fugui; Shen, Juan; Min, Dou; Ke, Lixia; Tian, Xin; Korpelainen, Helena; Li, Chunyang (2018)
    High Mn poisoned male and female Populus cathayana. The toxicity could be alleviated by exogenous ABA application. Intriguingly, ABA granted higher resistance to males than to females under high Mn stress because ABA could induce more blocking of Mn translocation to leaf in males than in females. Abscisic acid (ABA) is involved in plants' adaptive responses to various environmental stresses. However, little is known about the sex-related detoxification of ABA in plants under excess manganese (Mn) conditions. To reveal potentially different ABA detoxification mechanisms between Populus cathayana males and females against excess Mn exposure, photosynthesis performance, Mn2+ concentrations and morphologic changes were investigated. High Mn stress led to a more severe chloroplast destruction and, thus, greater reduction in the photosynthesis of P. cathayana females when compared to males. Under high Mn conditions, Mn reallocated mainly to leaves in females, while in males, it was distributed equally to roots and leaves. With the application of ABA, photosynthesis was restored more in males and more integrated grana in males than in females. It should be noted that Mn concentrations in males were lower in leaves and higher in roots and stems than those in females when treated with the combination of Mn and ABA. Conclusively, due to the reduction of root-shoot Mn transportation induced by ABA in P. cathayana males, males experienced less physiological injuries than do females, which suggest that males possess greater ABA-inducible resistance to Mn stress than do females.
  • Ikonen, Elina (2018)
    This review discusses advances in understanding how the controlled delivery of cholesterol between subcellular compartments is achieved and what novel experimental strategies are being employed to address this fundamental question. Recent work has focused on cholesterol-binding proteins that can facilitate directional cholesterol transfer between contacts of the ER and Golgi or late endosomal membranes. Increasing structural information on cholesterol-binding proteins, new modules engineered from them as well as improved imaging and gene editing techniques are providing valuable insights. There is also mounting information on how the crosstalk between cholesterol transport and nutrient signaling is orchestrated and how cellular fatty acid metabolism and cholesterol homeostasis are intertwined.
  • Rajamaki, Minna-Liisa; Sikorskaite-Gudziuniene, Sidona; Sarmah, Nandita; Varjosalo, Markku; Valkonen, Jari P. T. (2020)
    BackgroundInfection of plants by viruses interferes with expression and subcellular localization of plant proteins. Potyviruses comprise the largest and most economically damaging group of plant-infecting RNA viruses. In virus-infected cells, at least two potyviral proteins localize to nucleus but reasons remain partly unknown.ResultsIn this study, we examined changes in the nuclear proteome of leaf cells from a diploid potato line (Solanum tuberosum L.) after infection with potato virus A (PVA; genus Potyvirus; Potyviridae) and compared the data with that acquired for healthy leaves. Gel-free liquid chromatography-coupled to tandem mass spectrometry was used to identify 807 nuclear proteins in the potato line v2-108; of these proteins, 370 were detected in at least two samples of healthy leaves. A total of 313 proteins were common in at least two samples of healthy and PVA-infected leaves; of these proteins, 8 showed differential accumulation. Sixteen proteins were detected exclusively in the samples from PVA-infected leaves, whereas other 16 proteins were unique to healthy leaves. The protein Dnajc14 was only detected in healthy leaves, whereas different ribosomal proteins, ribosome-biogenesis proteins, and RNA splicing-related proteins were over-represented in the nuclei of PVA-infected leaves. Two virus-encoded proteins were identified in the samples of PVA-infected leaves.ConclusionsOur results show that PVA infection alters especially ribosomes and splicing-related proteins in the nucleus of potato leaves. The data increase our understanding of potyvirus infection and the role of nucleus in infection. To our knowledge, this is the first study of the nuclear proteome of potato leaves and one of the few studies of changes occurring in nuclear proteomes in response to plant virus infection.
  • Granberg, F.; Wang, X.; Chen, D.; Jin, K.; Wang, Y.; Bei, H.; Weber, W. J.; Zhang, Y.; More, K. L.; Nordlund, K.; Djurabekova, F. (2021)
    Due to virtually no solubility, He atoms implanted or created inside materials tend to form bubbles, which are known to damage material properties through embrittlement. Higher He density in nano-sized bubbles was observed both experimentally and computationally in Ni(100-x)Fex-alloy samples compared to Ni. The bubbles in the Ni(100-x)Fex-alloys were observed to be faceted, whereas in elemental Ni they were more spherical. Molecular dynamics simulations showed that stacking fault structures formed around bubbles at maximum He density. Higher Fe concentrations stabilize stacking fault structures, suppress evolution of dislocation network around bubbles and suppress complete dislocation emission, leading to higher He density. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd.
  • Makinen, Selina; Nguyen, Yen H.; Skrobuk, Paulina; Koistinen, Heikki A. (2017)
    Saturated fatty acids are implicated in the development of insulin resistance, whereas unsaturated fatty acids may have a protective effect on metabolism. We tested in primary human myotubes if insulin resistance induced by saturated fatty acid palmitate can be ameliorated by concomitant exposure to unsaturated fatty acid oleate. Primary human myotubes were pretreated with palmitate, oleate or their combination for 12 h. Glucose uptake was determined by intracellular accumulation of [H-3]-2-deoxy-d-glucose, insulin signalling and activation of endoplasmic reticulum (ER) stress by Western blotting, and mitochondrial reactive oxygen species (ROS) production by fluorescent dye MitoSOX. Exposure of primary human myotubes to palmitate impaired insulin-stimulated Akt-Ser(473), AS160 and GSK-3 beta phosphorylation, induced ER stress signalling target PERK and stress kinase JNK 54 kDa isoform. These effects were virtually abolished by concomitant exposure of palmitate-treated myotubes to oleate. However, an exposure to palmitate, oleate or their combination reduced insulin-stimulated glucose uptake. This was associated with increased mitochondrial ROS production in palmitate-treated myotubes co-incubated with oleate, and was alleviated by antioxidants MitoTempo and Tempol. Thus, metabolic and intracellular signalling events diverge in myotubes treated with palmitate and oleate. Exposure of human myotubes to excess fatty acids increases ROS production and induces insulin resistance.
  • Ebrahimi, Nashmin; Stoddard, Frederick L.; Hartikainen, Helina; Seppanen, Mervi M. (2019)
    Se deficiency is widespread in agricultural soils; hence, agronomic Se biofortification is an important strategy to overcome its deficiency in humans and animals. InFinland, fertilizers have been amended with inorganic Se for over 20years to reverse the negative effects of low Se content in feed and food. Plant species, climatic conditions, other nutrients and soil properties affect the efficiency of Se biofortification. The present twoyears' study compared the ability of oilseed rape, wheat and forage grasses to uptake fertilizer Se applied as sodium selenate in a sub-boreal environment. The effect of foliar N application on Se uptake was tested in thesecond year. Se concentration was determined in plant parts and in soil samples taken at the end of growth season in both years as well as from another plot where Se fertilizer had been used for 20years. Se fertilizer recovery in harvested wheat and oilseed rape was 1-16%, and in forage grasses was 52-64% in the first harvest and 15-19% in the second harvest. Foliar N application improved Se uptake only at the higher Se fertilizer level. The efficiency of biofortification depended on weather conditions, with forage grasses being the most reliable crop. Oilseed rape as a Se semi-accumulator had no advantage in Se biofortification in field conditions due to low translocation to seeds.
  • Vaara, Suvi T.; Ostermann, Marlies; Selander, Tuomas; Bitker, Laurent; Schneider, Antoine; Poli, Elettra; Hoste, Eric; Joannidis, Michael; Zarbock, Alexander; van Haren, Frank; Prowle, John; Pettilä, Ville; Bellomo, Rinaldo (2020)
    Abstract Background Fluid accumulation frequently coexists with acute kidney injury (AKI) and is associated with increased risk for AKI progression and mortality. Among septic shock patients, restricted use of resuscitation fluid has been reported to reduce the risk of worsening of AKI. Restrictive fluid therapy, however, has not been studied in the setting of established AKI. Here, we present the protocol and statistical analysis plan of the REstricted fluid therapy VERsus Standard trEatment in Acute Kidney Injury - the REVERSE-AKI trial that compares a restrictive fluid therapy regimen to standard therapy in critically ill patients with AKI. Methods REVERSE-AKI is an investigator-initiated, multinational, open-label, randomized, controlled, feasibility pilot trial conducted in 7 ICUs in 5 countries. We aim to randomize 100 critically ill patients with AKI to a restrictive fluid treatment regimen versus standard management. In the restrictive fluid therapy regimen, the daily fluid balance target is neutral or negative. The primary outcome is the cumulative fluid balance assessed after 72 hrs from randomization. Secondary outcomes include safety, feasibility, duration and severity of AKI, and outcome at 90 days (mortality and dialysis dependence). Conclusions This is the first multinational trial investigating the feasibility and safety of a restrictive fluid therapy regimen in critically ill patients with AKI.
  • Samkumar, Amos; Jones, Dan; Karppinen, Katja; Dare, Andrew P.; Sipari, Nina; Espley, Richard V.; Martinussen, Inger; Jaakola, Laura (2021)
    The biosynthesis of anthocyanins has been shown to be influenced by light quality. However, the molecular mechanisms underlying the light-mediated regulation of fruit anthocyanin biosynthesis are not well understood. In this study, we analysed the effects of supplemental red and blue light on the anthocyanin biosynthesis in non-climacteric bilberry (Vaccinium myrtillus L.). After 6 days of continuous irradiation during ripening, both red and blue light elevated concentration of anthocyanins, up to 12- and 4-folds, respectively, compared to the control. Transcriptomic analysis of ripening berries showed that both light treatments up-regulated all the major anthocyanin structural genes, the key regulatory MYB transcription factors and abscisic acid (ABA) biosynthetic genes. However, higher induction of specific genes of anthocyanin and delphinidin biosynthesis alongside ABA signal perception and metabolism were found in red light. The difference in red and blue light signalling was found in 9-cis-epoxycarotenoid dioxygenase (NCED), ABA receptor pyrabactin resistance-like (PYL) and catabolic ABA-8'hydroxylase gene expression. Red light also up-regulated expression of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) domain transporters, which may indicate involvement of these proteins in vesicular trafficking of anthocyanins during fruit ripening. Our results suggest differential signal transduction and transport mechanisms between red and blue light in ABA-regulated anthocyanin and delphinidin biosynthesis during bilberry fruit ripening.
  • Januszewski, Andrzej S.; Chen, David; Scott, Russell S.; O'Connell, Rachel L.; Aryal, Nanda R.; Sullivan, David R.; Watts, Gerald F.; Taskinen, Marja-Riitta; Barter, Philip J.; Best, James D.; Simes, R. John; Keech, Anthony C.; Jenkins, Alicia J. (2021)
    People with diabetes are at risk of chronic complications and novel biomarkers, such as Advanced glycation end-products (AGEs) may help stratify this risk. We assessed whether plasma low-molecular weight AGEs, also known as LMW-fluorophores (LMW-F), are associated with risk factors, predict complications, and are altered by fenofibrate in adults with type 2 diabetes. Plasma LMW-F were quantified at baseline, after six weeks fenofibrate, and one year post-randomisation to fenofibrate or placebo. LMW-F associations with existing and new composite vascular complications were determined, and effects of fenofibrate assessed. LMW-F correlated positively with age, glycated haemoglobin (HbA1c), pulse pressure, kidney dysfunction and inflammation; and negatively with urate, body mass index, oxidative stress and leptin, albeit weakly (r = 0.04-0.16, all p < 0.01). Independent determinants of LMW-F included smoking, diastolic blood pressure, prior cardiovascular disease or microvascular complications, Caucasian ethnicity, kidney function, HbA1c and diabetes duration (all p
  • Yan, Yan; Stoddard, Frederick L.; Neugart, Susanne; Sadras, Victor O.; Lindfors, Anders; Morales, Luis Orlando; Aphalo, Pedro J. (2019)
    Blue light and UV radiation shape a plant's morphology and development, but accession-dependent responses under natural conditions are unclear. Here we tested the hypothesis that two faba bean (Vicia faba L.) accessions adapted to different latitudes and altitudes vary in their responses to solar blue and UV light. We measured growth, physiological traits, phenolic profiles and expression of associated genes in a factorial experiment combining two accessions (Aurora, a Swedish cultivar adapted to high latitude and low altitude; ILB938, from the Andean region of Colombia and Ecuador, adapted to low latitude and high altitude) and four filter treatments created with plastic sheets: 1. transparent as control; 2. attenuated short UV (290-350 nm); 3. attenuated UV (290-400 nm); 4. attenuated blue and UV light. In both accessions, the exclusion of blue and UV light increased plant height and leaf area, and decreased transcript abundance of ELONGATED HYPOCOTYL 5 (HY5) and TYROSINE AMINOTRANSFERASE 3 (TAT3). Blue light and short UV induced the accumulation of epidermal and whole-leaf flavonoids, mainly quercetins, and the responses in the two accessions were through different glycosides. Filter treatments did not affect kaempferol concentration, but there were more tri-glycosides in Aurora and di-glycosides in ILB938. Furthermore, fewer quercetin glycosides were identified in ILB938. The transcript abundance was consistently higher in Aurora than in ILB938 for all seven investigated genes: HY5, TAT3, CHALCONE SYNTHASE (CHS), CHALCONE ISOMERASE (CHI), DON-GLUCOSYLTRANSFERASE 1 (DOGT1), ABA INSENSITIVE 2 (ABI2), AUXIN-INDUCIBLE 2-27 (IAA5). The two largest differences in transcript abundance between the two accessions across treatments were 132-fold in CHS and 30-fold in DOGT1 which may explain the accession-dependent glycosylation patterns. Our findings suggest that agronomic selection for adaptation to high altitude may favour phenotypes with particular adaptations to the light environment, including solar UV and blue light.
  • REVERSE-AKI Study Team; Vaara, Suvi T.; Ostermann, Marlies; Bitker, Laurent; Pettilä, Ville (2021)
    Purpose We compared a restrictive fluid management strategy to usual care among critically ill patients with acute kidney injury (AKI) who had received initial fluid resuscitation. Methods This multicenter feasibility trial randomized 100 AKI patients 1:1 in seven ICUs in Europe and Australia. Restrictive fluid management included targeting negative or neutral daily fluid balance by minimizing fluid input and/or enhancing urine output with diuretics administered at the discretion of the clinician. Fluid boluses were administered as clinically indicated. The primary endpoint was cumulative fluid balance 72 h from randomization. Results Mean (SD) cumulative fluid balance at 72 h from randomization was - 1080 mL (2003 mL) in the restrictive fluid management arm and 61 mL (3131 mL) in the usual care arm, mean difference (95% CI) - 1148 mL (- 2200 to - 96) mL, P = 0.033. Median [IQR] duration of AKI was 2 [1-3] and 3 [2-7] days, respectively (median difference - 1.0 [- 3.0 to 0.0], P = 0.071). Altogether, 6 out of 46 (13%) patients in the restrictive fluid management arm and 15 out of 50 (30%) in the usual care arm received renal replacement therapy (RR 0.42; 95% CI 0.16-0.91), P = 0.043. Cumulative fluid balance at 24 h and 7 days was lower in the restrictive fluid management arm. The dose of diuretics was not different between the groups. Adverse events occurred more frequently in the usual care arm. Conclusions In critically ill patients with AKI, a restrictive fluid management regimen resulted in lower cumulative fluid balance and less adverse events compared to usual care. Larger trials of this intervention are justified.
  • Plociniczak, Tomasz; Sinkkonen, Aki; Romantschuk, Martin; Sulowicz, Stawomir; Piotrowska-Seget, Zofia (2016)
    Environmental pollution by heavy metals has become a serious problem in the world. Phytoextraction, which is one of the plant-based technologies, has attracted the most attention for the bioremediation of soils polluted with these contaminants. The aim of this study was to determine whether the multiple-tolerant bacterium. Brevibacterium casei MH8a isolated from the heavy metal-contaminated rhizosphere soil of Sinapis alba L., is able to promote plant growth and enhance Cd, Zn, and Cu uptake by white mustard under laboratory conditions. Additionally, the ability of the rifampicin-resistant spontaneous mutant of MH8a to colonize plant tissues and its mechanisms of plant growth promotion were also examined. In order to assess the ecological consequences of bioaugmentation on autochthonous bacteria, the phospholipid fatty acid (PLFA) analysis was used. The MH8a strain exhibited the ability to produce ammonia, 1-amino-cyclopropane-1-carboxylic acid deaminase, indole 3-acetic acid and HCN but was not able to solubilize inorganic phosphate and produce siderophores. Introduction of MH8a into soil significantly increased S, alba biomass and the accumulation of Cd (208%), Zn (86%), and Cu (39%) in plant shoots in comparison with those grown in non-inoculated soil. Introduced into the soil, MH8a was able to enter the plant and was found in the roots and leaves of inoculated plants thus indicating its endophytic features. PLFA analysis revealed that the MH8a that was introduced into soil had a temporary influence on the structure of the autochthonous bacterial communities. The plant growth-promoting features of the MH8a strain and its ability to enhance the metal uptake by white mustard and its long-term survival in soil as well as its temporary impact on autochthonous microorganisms make the strain a suitable candidate for the promotion of plant growth and the efficiency of phytoextraction.
  • Salo, Veijo T.; Li, Shiqian; Vihinen, Helena; Hölttä-Vuori, Maarit; Szkalisity, Abel; Horvath, Peter; Belevich, Ilya; Peränen, Johan; Thiele, Christoph; Somerharju, Pentti; Zhao, Hongxia; Santinho, Alexandre; Thiam, Abdou Rachid; Jokitalo, Eija; Ikonen, Elina (2019)
    Seipin is an oligomeric integral endoplasmic reticulum (ER) protein involved in lipid droplet (LD) biogenesis. To study the role of seipin in LD formation, we relocalized it to the nuclear envelope and found that LDs formed at these new seipin-defined sites. The sites were characterized by uniform seipin-mediated ER-LD necks. At low seipin content, LDs only grew at seipin sites, and tiny, growth-incompetent LDs appeared in a Rab18-dependent manner. When seipin was removed from ER-LD contacts within 1 h, no lipid metabolic defects were observed, but LDs became heterogeneous in size. Studies in seipin-ablated cells and model membranes revealed that this heterogeneity arises via a biophysical ripening process, with triglycerides partitioning from smaller to larger LDs through droplet-bilayer contacts. These results suggest that seipin supports the formation of structurally uniform ER-LD contacts and facilitates the delivery of triglycerides from ER to LDs. This counteracts ripening-induced shrinkage of small LDs.
  • Kröger, Markus; Nygren, Anja (2020)
    The concepts of resource frontier and commodity frontier are often treated interchangeably. This article suggests the benefits of clarifying these concepts because frontiers remain important analytics for understanding drastic land-use changes and other socio-environmental transformations. Based on long-term field research in different parts of South and Central America, we use frontier concepts as heuristic devices to analyze heterogeneous frontier situations and make broader generalizations. Our synchronic and diachronic analyses of frontier dynamics elucidate different frontier modalities and shifting frontier expansions. The concept of commoditizing resource frontier is introduced to explain recent frontier-makings in the Brazilian Amazonia and Cerrado and in the Nicaraguan Rio San Juan. Although earlier frontier research took a short-sighted time perspective and created conceptualizations based on a single modality of a particular period, our longitudinal analysis shows that drastic changes and complex overlappings are the hallmarks of frontier dynamics.
  • Falconi, Marta Tecla; von Lerber, Annakaisa; Ori, Davide; Marzano, Frank Silvio; Moisseev, Dmitri (2018)
    Radar-based snowfall intensity retrieval is investigated at centimeter and millimeter wavelengths using co-located ground-based multi-frequency radar and video-disdrometer observations. Using data from four snowfall events, recorded during the Biogenic Aerosols Effects on Clouds and Climate (BAECC) campaign in Finland, measurements of liquid-water-equivalent snowfall rate S are correlated to radar equivalent reflectivity factors Z(e), measured by the Atmospheric Radiation Measurement (ARM) cloud radars operating at X, Ka and W frequency bands. From these combined observations, power-law Z(e)-S relationships are derived for all three frequencies considering the influence of riming Using microwave radiometer observations of liquid water path, the measured precipitation is divided into lightly, moderately and heavily rimed snow. Interestingly lightly rimed snow events show a spectrally distinct signature of Z(e)-S with respect to moderately or heavily rimed snow cases. In order to understand the connection between snowflake microphysical and multi-frequency backscattering properties, numerical simulations are performed by using the particle size distribution provided by the in situ video disdrometer and retrieved ice particle masses. The latter are carried out by using both the T-matrix method (TMM) applied to soft-spheroid particle models with different aspect ratios and exploiting a pre-computed discrete dipole approximation (DDA) database for rimed aggregates. Based on the presented results, it is concluded that the soft-spheroid approximation can be adopted to explain the observed multifrequency Z(e)-S relations if a proper spheroid aspect ratio is selected. The latter may depend on the degree of riming in snowfall. A further analysis of the backscattering simulations reveals that TMM cross sections are higher than the DDA ones for small ice particles, but lower for larger particles. The differences of computed cross sections for larger and smaller particles are compensating for each other. This may explain why the soft-spheroid approximation is satisfactory for radar reflectivity simulations under study.