326 research outputs found

    Coexistence of silver fir and beech in the Dinaric Alps : implications for conservation and management of silver fir

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    Drevesna sestava jelovo-bukovih gozdov se v prostoru in času spreminja. Nanjo vplivajo številni naravni in antropogeni dejavniki, ki delujejo neposredno ali posredno. Oblikovanje usmeritev za gojenje gozdov zato zahteva dobro poznavanje delovanja lokalnih ekoloških, zgodovinskih, gospodarskih in splošnih okoljskih dejavnikov. V prispevku prikazujemo sintezo štirih skupin raziskav, ki smo jih izpeljali v dinarskih jelovo-bukovih gozdovih v zadnjem desetletju in obravnavajo: 1) ekologijo pomlajevanja v manjših in srednjih vrzelih, 2) odziv sestojev v pragozdu Perućica na motnje srednjih jakosti (vetrolomi), 3) dolgoročne spremembe v vrstni sestavi pragozdov v jugovzhodni Evropi, in 4) odvisnost pomlajevanja v gospodarskih gozdovih od gozdnogojitvenega sistema. Namen prispevka je prikazati vlogo jelke v razvoju jelovo-bukovega gozda ter poudariti procese, ki vodijo v njeno sobivanje ali izločanje. Raziskave ekologije pomlajevanja nakazujejo, da je jelka uspešnejša na posebnih mikrorastiščih (hladnejše in vlažnejše razmere, odmrla drevesa, večja skalovitost, nižji pH tal, skromne svetlobe razmere). Na vetrolomnih površinah srednjih jakosti prevlada bukev, jelka pa se nasemeni kasneje v strnjena bukova mladovja. Naše raziskave niso potrdile hipoteze o lažjem uveljavljanju jelke v večjih sestojnih vrzelih gospodarskih gozdov. Spremembe vrstne sestave pragozdov v Sloveniji in jugovzhodni Evropi nakazujejo nazadovanje jelke v zadnjih petdesetih letih, kar je posledica več skupin vzrokov, še posebej zračnega onesnaženja in objedanja po divjadi. V Sloveniji je zmanjševanje deleža jelke v Dinaridih izrazito hitro. Primerjave z jugovzhodno Evropo kažejo, da so sicer raznovrstne strategije uveljavljanja jelke v Sloveniji neuspešne zaradi visokih gostot velikih rastlinojedih parkljarjev.The tree species composition of silver fir and beech forests has changed in space and time due to a number of direct and indirect natural and anthropogenic causal factors. Forming silvicultural guidelines, therefore, requires a sufficient understanding of the ecological, historical, economic and general environmental factors that influence silver fir-beech forests. In this paper, we present a synthesis of four research projects carried out in Dinaric silver fir-beech forests in the last decade: 1) regeneration ecology in small and medium canopy gaps2) stand response to intermediate wind disturbance in the old-growth silver fir-beech Perućica forest3) long-term changes in tree species composition of old-growth forests in South East Europeand 4) interdependence between regeneration and silvicultural systems.The aim of the paper is to show the role of silver fir in the development of silver fir-beech forest, and to highlight the processes that lead to its coexistence or exclusion. Research on the ecology of regeneration suggests that silver fir regenerates better on special microsites (e.g. coolersites with more soil moisture, CWD, high rock coverage, lower pH of the soil, poor light conditions). In medium sized gaps beech is dominant, while silver fir establishes itself later under the young beech canopy. Our research did not confirm the hypothesis of better regeneration success of silver fir in larger canopy gaps in managed forests. Repeated inventories from forest reserves in Slovenia and South-Eastern Europe show that silver fir declined in the last fifty years due to a variety of causes, primarily from air pollution and ungulate browsing. In Slovenia in particular, a drastic reduction of the share of silver fir occurred rapidly. Comparisons with South-Eastern Europe suggest that a wide range of regeneration strategies of silver fir in Slovenia failed because of high densities of ungulates

    Real-time kinetic binding studies at attomolar concentrations in solution phase using a single-stage opto-biosensing platform based upon infrared surface plasmons

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    Here we present a new generic opto-bio-sensing platform combining immobilised aptamers on an infrared plasmonic sensing device generated by nano-structured thin film that demonstrates amongst the highest index spectral sensitivities of any optical fibre sensor yielding on average 3.4 × 104 nm/RIU in the aqueous index regime (with a figure of merit of 330) This offers a single stage, solution phase, atto-molar detection capability, whilst delivering real-time data for kinetic studies in water-based chemistry. The sensing platform is based upon optical fibre and has the potential to be multiplexed and used in remote sensing applications. As an example of the highly versatile capabilities of aptamer based detection using our platform, purified thrombin is detected down to 50 attomolar concentration using a volume of 1mm3 of solution without the use of any form of enhancement technique. Moreover, the device can detect nanomolar levels of thrombin in a flow cell, in the presence of 4.5% w/v albumin solution. These results are important, covering all concentrations in the human thrombin generation curve, including the problematic initial phase. Finally, selectivity is confirmed using complementary and non-complementary DNA sequences that yield performances similar to those obtained with thrombin

    Thyroid Hormone May Regulate mRNA Abundance in Liver by Acting on MicroRNAs

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    MicroRNAs (miRNAs) are extensively involved in diverse biological processes. However, very little is known about the role of miRNAs in mediating the action of thyroid hormones (TH). Appropriate TH levels are known to be critically important for development, differentiation and maintenance of metabolic balance in mammals. We induced transient hypothyroidism in juvenile mice by short-term exposure to methimazole and perchlorate from post natal day (PND) 12 to 15. The expression of miRNAs in the liver was analyzed using Taqman Low Density Arrays (containing up to 600 rodent miRNAs). We found the expression of 40 miRNAs was significantly altered in the livers of hypothyroid mice compared to euthyroid controls. Among the miRNAs, miRs-1, 206, 133a and 133b exhibited a massive increase in expression (50- to 500-fold). The regulation of TH on the expression of miRs-1, 206, 133a and 133b was confirmed in various mouse models including: chronic hypothyroid, short-term hyperthyroid and short-term hypothyroid followed by TH supplementation. TH regulation of these miRNAs was also confirmed in mouse hepatocyte AML 12 cells. The expression of precursors of miRs-1, 206, 133a and 133b were examined in AML 12 cells and shown to decrease after TH treatment, only pre-mir-206 and pre-mir-133b reached statistical significance. To identify the targets of these miRNAs, DNA microarrays were used to examine hepatic mRNA levels in the short-term hypothyroid mouse model relative to controls. We found transcripts from 92 known genes were significantly altered in these hypothyroid mice. Web-based target predication software (TargetScan and Microcosm) identified 14 of these transcripts as targets of miRs-1, 206, 133a and 133b. The vast majority of these mRNA targets were significantly down-regulated in hypothyroid mice, corresponding with the up-regulation of miRs-1, 206, 133a and 133b in hypothyroid mouse liver. To further investigate target genes, miR-206 was over-expressed in AML 12 cells. TH treatment of cells over-expressing miR-206 resulted in decreased miR-206 expression, and a significant increase in two predicted target genes, Mup1 and Gpd2. The results suggest that TH regulation of these genes may occur secondarily via miR-206. These studies provide new insight into the role of miRNAs in mediating TH regulation of gene expression

    Where are we now with European forest multi-taxon biodiversity and where can we head to?

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    The European biodiversity and forest strategies rely on forest sustainable management (SFM) to conserve forest biodiversity. However, current sustainability assessments hardly account for direct biodiversity indicators. We focused on forest multi-taxon biodiversity to: i) gather and map the existing information; ii) identify knowledge and research gaps; iii) discuss its research potential. We established a research network to fit data on species, standing trees, lying deadwood and sampling unit description from 34 local datasets across 3591 sampling units. A total of 8724 species were represented, with the share of common and rare species varying across taxonomic classes: some included many species with several rare ones (e.g., Insecta); others (e.g., Bryopsida) were represented by few common species. Tree-related structural attributes were sampled in a subset of sampling units (2889; 2356; 2309 and 1388 respectively for diameter, height, deadwood and microhabitats). Overall, multitaxon studies are biased towards mature forests and may underrepresent the species related to other developmental phases. European forest compositional categories were all represented, but beech forests were overrepresented as compared to thermophilous and boreal forests. Most sampling units (94%) were referred to a habitat type of conservation concern. Existing information may support European conservation and SFM strategies in: (i) methodological harmonization and coordinated monitoring; (ii) definition and testing of SFM indicators and thresholds; (iii) data-driven assessment of the effects of environmental and management drivers on multi-taxon forest biological and functional diversity, (iv) multi-scale forest monitoring integrating in-situ and remotely sensed information. Forest biodiversity Multi-taxon Sustainable management Biodiversity conservation Forest stand structurepublishedVersio

    Deep brain stimulation of the anterior nucleus of the thalamus in drug-resistant epilepsy in the MORE multicenter patient registry

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    Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background and objectives: The efficacy of deep brain stimulation of the anterior nucleus of the thalamus (ANT DBS) in patients with drug-resistant epilepsy (DRE) was demonstrated in the double-blind Stimulation of the Anterior Nucleus of the Thalamus for Epilepsy randomized controlled trial. The Medtronic Registry for Epilepsy (MORE) aims to understand the safety and longer-term effectiveness of ANT DBS therapy in routine clinical practice. Methods: MORE is an observational registry collecting prospective and retrospective clinical data. Participants were at least 18 years old, with focal DRE recruited across 25 centers from 13 countries. They were followed for at least 2 years in terms of seizure frequency (SF), responder rate (RR), health-related quality of life (Quality of Life in Epilepsy Inventory 31), depression, and safety outcomes. Results: Of the 191 patients recruited, 170 (mean [SD] age of 35.6 [10.7] years, 43% female) were implanted with DBS therapy and met all eligibility criteria. At baseline, 38% of patients reported cognitive impairment. The median monthly SF decreased by 33.1% from 15.8 at baseline to 8.8 at 2 years (p 10 implantations) had 42.8% reduction in median monthly SF by 2 years in comparison with 25.8% in low-volume center. In patients with cognitive impairment, the reduction in median monthly SF was 26.0% by 2 years compared with 36.1% in patients without cognitive impairment. The most frequently reported adverse events were changes (e.g., increased frequency/severity) in seizure (16%), memory impairment (patient-reported complaint, 15%), depressive mood (patient-reported complaint, 13%), and epilepsy (12%). One definite sudden unexpected death in epilepsy case was reported. Discussion: The MORE registry supports the effectiveness and safety of ANT DBS therapy in a real-world setting in the 2 years following implantation. Classification of evidence: This study provides Class IV evidence that ANT DBS reduces the frequency of seizures in patients with drug-resistant focal epilepsy.The MORE registry was sponsored and funded by Medtronic, plc.info:eu-repo/semantics/publishedVersio

    The Microphenotron: a robotic miniaturized plant phenotyping platform with diverse applications in chemical biology

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    Background Chemical genetics provides a powerful alternative to conventional genetics for understanding gene function. However, its application to plants has been limited by the lack of a technology that allows detailed phenotyping of whole-seedling development in the context of a high-throughput chemical screen. We have therefore sought to develop an automated micro-phenotyping platform that would allow both root and shoot development to be monitored under conditions where the phenotypic effects of large numbers of small molecules can be assessed. Results The ‘Microphenotron’ platform uses 96-well microtitre plates to deliver chemical treatments to seedlings of Arabidopsis thaliana L. and is based around four components: (a) the ‘Phytostrip’, a novel seedling growth device that enables chemical treatments to be combined with the automated capture of images of developing roots and shoots; (b) an illuminated robotic platform that uses a commercially available robotic manipulator to capture images of developing shoots and roots; (c) software to control the sequence of robotic movements and integrate these with the image capture process; (d) purpose-made image analysis software for automated extraction of quantitative phenotypic data. Imaging of each plate (representing 80 separate assays) takes 4 min and can easily be performed daily for time-course studies. As currently configured, the Microphenotron has a capacity of 54 microtitre plates in a growth room footprint of 2.1 m², giving a potential throughput of up to 4320 chemical treatments in a typical 10 days experiment. The Microphenotron has been validated by using it to screen a collection of 800 natural compounds for qualitative effects on root development and to perform a quantitative analysis of the effects of a range of concentrations of nitrate and ammonium on seedling development. Conclusions The Microphenotron is an automated screening platform that for the first time is able to combine large numbers of individual chemical treatments with a detailed analysis of whole-seedling development, and particularly root system development. The Microphenotron should provide a powerful new tool for chemical genetics and for wider chemical biology applications, including the development of natural and synthetic chemical products for improved agricultural sustainability
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