258 research outputs found
Marine ecosystem services: Linking indicators to their classification
© 2014 Elsevier Ltd. All rights reserved. There is a multitude of ecosystem service classifications available within the literature, each with its own advantages and drawbacks. Elements of them have been used to tailor a generic ecosystem service classification for the marine environment and then for a case study site within the North Sea: the Dogger Bank. Indicators for each of the ecosystem services, deemed relevant to the case study site, were identified. Each indicator was then assessed against a set of agreed criteria to ensure its relevance and applicability to environmental management. This paper identifies the need to distinguish between indicators of ecosystem services that are entirely ecological in nature (and largely reveal the potential of an ecosystem to provide ecosystem services), indicators for the ecological processes contributing to the delivery of these services, and indicators of benefits that reveal the realized human use or enjoyment of an ecosystem service. It highlights some of the difficulties faced in selecting meaningful indicators, such as problems of specificity, spatial disconnect and the considerable uncertainty about marine species, habitats and the processes, functions and services they contribute to
A co-transcriptional ribosome assembly checkpoint controls nascent large ribosomal subunit maturation.
peer reviewedDuring transcription of eukaryotic ribosomal DNA in the nucleolus, assembly checkpoints exist that guarantee the formation of stable precursors of small and large ribosomal subunits. While the formation of an early large subunit assembly checkpoint precedes the separation of small and large subunit maturation, its mechanism of action and function remain unknown. Here, we report the cryo-electron microscopy structure of the yeast co-transcriptional large ribosomal subunit assembly intermediate that serves as a checkpoint. The structure provides the mechanistic basis for how quality-control pathways are established through co-transcriptional ribosome assembly factors, that structurally interrogate, remodel and, together with ribosomal proteins, cooperatively stabilize correctly folded pre-ribosomal RNA. Our findings thus provide a molecular explanation for quality control during eukaryotic ribosome assembly in the nucleolus
The role of interdisciplinary collaboration for stated preference methods to value marine environmental goods and ecosystem services
With the increasing use of environmental valuation methods in coastal, marine and deep-sea settings, there is a growing need for the collaboration of natural scientists and environmental economists. Stated preference valuation methods in particular need to be based on sound natural science information and translate such information to be used in social surveys. This paper uses three applications to make explicit the flow of information between different disciplines in the preparation and implementation of stated preference studies. One approach for facilitating this flow is to increase knowledge and understanding of natural scientists on these methods. To address this, this paper highlights key opportunities and pitfalls and demonstrates those in the context of three case studies. It therefore provides guidance on stated preference valuation for natural scientists rather than for economists
Spexin-expressing neurons in the magnocellular nuclei of the human hypothalamus
Neuropeptides are involved in numerous brain activities being responsible for a wide spectrum of higher mental functions. The purpose of this concise, structural and qualitative investigation was to map the possible immunoreactivity of the novel neuropeptide spexin (SPX) within the human magnocellular hypothalamus. SPX is a newly identified peptide, a natural ligand for the galanin receptors (GALR) 2/3, with no molecular structure similarities to currently known regulatory factors. SPX seems to have multiple physiological functions, with an involvement in reproduction and food-intake regulation recently revealed in animal studies. For the first time we describe SPX expressing neurons in the supraoptic (SON) and paraventricular (PVN) nuclei of the human hypothalamus using immunohistochemical and fluorescent methods, key regions involved in the mechanisms of osmotic homeostasis, energy expenditure, consummatory behaviour, reproductive processes, social recognition and stress responses. The vast majority of neurons located in both examined neurosecretory nuclei show abundant SPX expression and this may indirectly implicate a potential contribution of SPX signalling to the hypothalamic physiology in the human brain. © 2020 Elsevier B.V
Contribution to the flora of Asian and European countries : new national and regional vascular plant records, 9
Influence of powder/liquid ratio on the radiodensity and diametral tensile strength of glass ionomer cements
OBJECTIVE: To determine the influence of P/L ratio on the radiodensity and diametral tensile strength (DTS) of glass ionomer cements. MATERIAL AND METHODS: There were 2 factors under study: P/L ratio (manufacturer's recommended P/L ratio and a 50% reduced P/L ratio), and materials (Vitro Molar, Vitro Fil, Vitro Cem conventional GICs and Vitro Fil LC, Ortho Glass LC RMGICs). Five 1-mm-thick samples of each material-P/L ratio were produced for radiodensity evaluation. Samples were x-ray exposed onto Digora phosphor plate and radiodensity was obtained using the software Digora for Windows 2.5 Rev 0. For DTS, five (4.0x8.0 mm) cylinder samples of each material were tested (0.5 mm/min). Data were subjected to one- and two-way ANOVA (5x2) followed by Tukey's HSD test, or Kruskal-Wallis and Dunn's method. For paired comparisons, t-test or Mann-Whitney test were used (a=0.05). RESULTS: There was a significant interaction (P=0.001) for the studied factors (materials vs. P/L ratio). Reduced P/L ratio resulted in significantly lower DTS for the RMGICs, but radiodensity was affected for all materials (P<0.05). CONCLUSIONS: Reduced P/L ratio affected properties of the tested glass ionomer cements. RMGICs were more susceptible to lower values of DTS, but radiodensity decreased for all materials following P/L ratio reduction
Euro+Med-Checklist Notulae, 14
Abstract: This is the fourteenth of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. This instalment deals with the families Apocynaceae, Compositae, Crassulaceae, Cyperaceae, Euphorbiaceae, Gramineae, Leguminosae, Nyctaginaceae, Onagraceae, Orobanchaceae, Rubiaceae, Solanaceae and Umbelliferae. It includes new country and area records and taxonomic and distributional considerations for taxa in Acalypha, Bupleurum, Carex, Datura, Epilobium, Eragrostis, Galium, Leontodon, Mirabilis, Nerium, Orobanche, Phelipanche, Rhinanthus, Saccharum, Sedum, Trifolium, Tripleurospermum and Willemetia. Citation For the whole article: Raab-Straube E. von & Raus Th. (ed.) 2021: Euro+Med-Checklist Notulae, 14.-Willdenowia 51: 355-369. For a single contribution (example): Bergmeier E. 2021: Leontodon longirostris (Finch & P. D. Sell) Talavera-Pp. 356-357 in: Raab-Straube E. von & Raus Th. (ed.), Euro+Med-Checklist Notulae, 14.-Willdenowia 51: 355-369. https://doi.org/10.3372/wi.51.51304 Version of record first published online on 30 November 2021 ahead of inclusion in December 2021 issue
New national and regional plant records : contribution to the flora of the old world countries, 2
This paper presents new data on the occurrence of 34 vascular plant species from Europe (five countries), Asia (seven countries) and Africa (six countries) as well as one moss species from Asia (Uzbekistan). For each species, synonyms, taxonomy with remarks on recognition and differentiation of the species from the most similar taxa occurring in a given area, general distribution, habitat preferences, as well as a list of recorded localities (often far from the previously known distribution range) are presented. As a result of the taxonomic investigation, we described one new variety Stipa drobovii var. hajastanica M. Nobis & Klichowska, and proposed three new combinations: Orobanche teucrii subsp. sideritidis (Huter, Porta & Rigo) Ó. Sánchez & Piwow., Phelipanche pyramidalis (Reut.) Ó. Sánchez & Piwow., and Ph. reuteriana var. lanuginosa (Maire) Ó. Sánchez & Piwow. Additionally, the lectotypes for Ph. pyramidalis and Ph. reuteriana var. lanuginosa are here designated
Top-down CO emission estimates using TROPOMI CO data in the TM5-4DVAR (r1258) inverse modeling suit
Carbon monoxide in the atmosphere adversely affects air quality and climate, making knowledge about its sources crucial. However, current global bottom-up emission estimates retain significant uncertainties. In this study, we attempt to reduce these uncertainties by optimizing emission estimates for the second half of the year 2018 on a global scale with a focus on the Northern Hemisphere through the top-down approach of inverse modeling. Specifically, we introduce observations from the TROPOspheric Monitoring Instrument (TROPOMI) into the TM5-4DVAR model. The emissions are further constrained using NOAA surface flask measurements. We conducted six experiments to investigate the impact of data use in our inversions, varying the a priori emissions and observational datasets.
Notably, the inversion driven by satellite observations alone agrees with flask measurements south of 55° N almost as well as the inversions that included those measurements. This indicates that our method could be suitable for inversions based purely on satellite observations. Compared to the bottom-up estimates, all experiments result in strong (up to 75 %) broad-scale emission reductions in China and India throughout the entire inversion period. Part of the reduction in China can be attributed to policy and technology changes (e.g., coal to gas). Additionally, the OH climatology used to simulate chemical loss appears to be underestimated in that region, which also skews the inversions towards lower emissions. In the experiments that include the surface flask measurements, we find strong localized emission increments over Europe and the Sahara, which are traced back to limitations of the model in reproducing point measurements on mountain tops.</p
Mechanical Properties of Dual-Cured Resin Luting Agents for Ceramic Restoration
Purpose: The aim of the present study was to evaluate the mechanical properties including surface hardness, flexural strength, and flexural modulus of two dual-cured resin luting agents (New Resin Cement [NRC] and Variolink II [VLII]) irradiated through four different thickness of leucite ceramics (0, 1, 2, and 3 mm) and their shear bond strength to zirconia ceramic (Cercon) using each ceramic primer. Materials and Methods: Knoop hardness was measured on a thin layer of resin luting agent on the ceramic surface. Three-point bending tests were performed after 24 h storage at 37°C. Two different-shaped zirconia ceramic specimens with or without sandblasting with alumina were treated with each primer. The specimens were then cemented together with each resin luting agent. Half of the specimens were stored in water at 37°C for 24 h and the other half were thermocycled 5,000 times. Results: VLII revealed statistically higher Knoop hardness and flexural modulus than NRC for each thickness of ceramic. No significant differences in flexural strength were observed between VLII and NRC for each ceramic spacer. Reduction of the mechanical properties with increase of ceramic thickness varied for each property. However, these properties were similar between the two materials. Blasting with alumina was significantly effective for increasing shear bond strength of both resin luting agents before and after thermal cycling. The use of New Ceramic Primer showed the highest shear bond strength and maintained bond durability after 5,000 thermocycles. Conclusion: Mechanical properties of NRC dual-cured resin luting agent appear adequate for ceramic restorations.This is an electronic version of an Article published in Journal of Prosthodontics 16(5): 370-376, 2007
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