| 1. |
- Sümegi, Pál, et al.
(author)
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Comparison of High-Resolution 14C and Luminescence-Based Chronologies of the MIS 2 Madaras Loess/Paleosol Sequence, Hungary : Implications for Chronological Studies
- 2022
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In: Quaternary. - : MDPI. - 2571-550X. ; 5:4
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Journal article (peer-reviewed)abstract
- Numerous loess/paleosol sequences (LPS) in the Carpathian Basin span the period of Marine Isotope Stage (MIS) 2 and the last glacial maximum (LGM). Nevertheless, only two known records-Madaras and Dunaszekcso-preserve highly resolved records with absolute chronologies with minimal uncertainties, which enable the meaningful assessment of feedbacks and short-term climatic fluctuations over this period. The Madaras profile is located at the northern margin fringe of the Bacska loess plateau; Dunaszekcso, located on the Danube to its west, yields a chronology built on over 100 C-14 dates yet spans only part of MIS 2, missing half of the LGM including its peak. Here, we add to the previously published C-14 chronology for Madaras (15 dates) with an additional 17 C-14 and luminescence ages. Resulting age models built solely on quartz OSL and feldspar pIRIRSL data underestimate the C-14 based chronology, which is likely based on inaccuracies related to luminescence signal behavior; we observe age underestimations associated with unusual quartz behavior and significant signal loss, a phenomenon also observed in Serbian and Romanian loess, which may relate to non-sensitized grains from proximal sources. Our new chronology provides higher resolution than hitherto possible, yielding consistent 2 sigma uncertainties of similar to 150-200 years throughout the entire sequence. Our study indicates that the addition of further dates may not increase the chronological precision significantly. Additionally, the new age model is suitable for tackling centennial-scale changes. The mean sedimentation rate based on our new age-depth model (10.78 +/- 2.34 years/cm) is the highest yet recorded in the Carpathian Basin for MIS 2. The resolution of our age model is higher than that for the Greenland NGRIP ice core record. The referred horizons in our profile are all characterized by a drop in accumulation and a higher sand input, the latter most likely deriving from nearby re-exposed sand dunes.
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| 2. |
- Kiss, Anita, et al.
(author)
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Synthesis of novel 17-triazolyl-androst-5-en-3-ol epimers via Cu(I)-catalyzed azide-alkyne cycloaddition and their inhibitory effect on 17 alpha-hydroxylase/ C-17,C-20-lyase
- 2018
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In: Steroids. - : Elsevier BV. - 0039-128X .- 1878-5867. ; 135, s. 79-91
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Journal article (peer-reviewed)abstract
- The regioselective Cu(I)-catalyzed 1,3-dipolar cycloaddition of 17 alpha- and 17 beta-azidoandrost-5-en-3 beta-ol epimers (3b and 5b) with different terminal alkynes afforded novel 1,4-substituted triazolyl derivatives (8a-k and 9a-k). For the preparation of 5'-iodo-l',2',3'-triazoles (8m-n and 9m-n), an improved method was developed, directly from steroidal azides and terminal alkynes, in reaction mediated by Cul and IC1 as iodinating agents. Acetolysis and subsequent hydrolysis of 8n and 9n yielded 5'-hydroxy-l',2',3'-triazoles 8o and 9o. The inhibitory effect of 8a-o, 9a-o, 3, and 5 on rat testicular C-17,C-20-lyase was investigated by means of an in vitro radioincubation technique. The results revealed that the C-17 epimers of steroidal triazoles influence the C-17,C-20-lyase effect. Inhibitors were found only in the 17 alpha-triazolyl series (8a-o), whereas in the C-17 azide pair the 17 beta compound (5b) was more potent.
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| 3. |
- Kramer, Z., et al.
(author)
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A Lightweight Performance Enhancing Proxy for Evolved Protocols and Networks
- 2020
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In: IEEE International Workshop on Computer Aided Modeling and Design of Communication Links and Networks, CAMAD. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781728163390
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Conference paper (peer-reviewed)abstract
- In this paper we present the design and prototype implementation of a multi-domain congestion control framework based on a non-ossifying Lightweight Performance Enhancing Proxy. We demonstrate that our solution can be both used for evolved protocols such as end-to-end encrypted QUIC and for evolved cellular access networks like 5G. We also show the performance of our Multi-Domain Congestion Control algorithm by a simulation study. Moreover, we expose its behavior in realistic use cases like sudden capacity changes in 5G mmWave cellular networks. Our results highlight that significant performance improvements can be achieved by cooperative traffic management frameworks in protocols and networks of the future.
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| 4. |
- Pironi, Loris, et al.
(author)
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Characteristics of adult patients with chronic intestinal failure due to short bowel syndrome: An international multicenter survey
- 2021
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In: Clinical Nutrition ESPEN. - : Elsevier BV. - 2405-4577. ; 45, s. 433-441
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Journal article (peer-reviewed)abstract
- Background and aims: The case-mix of patients with intestinal failure due to short bowel syndrome (SBS-IF) can differ among centres and may also be affected by the timeframe of data collection. Therefore, the ESPEN international multicenter cross-sectional survey was analyzed to compare the characteristics of SBS-IF cohorts collected within the same timeframe in different countries. Methods: The study included 1880 adult SBS-IF patients collected in 2015 by 65 centres from 22 countries. The demographic, nutritional, SBS type (end jejunostomy, SBS-J; jejuno-colic anastomosis, SBS-JC; jejunoileal anastomosis with an intact colon and ileocecal valve, SBS-JIC), underlying disease and intravenous supplementation (IVS) characteristics were analyzed. IVS was classified as fluid and electrolyte alone (FE) or parenteral nutrition admixture (PN). The mean daily IVS volume, calculated on a weekly basis, was categorized as <1, 1–2, 2–3 and >3 L/day. Results: In the entire group: 60.7% were females and SBS-J comprised 60% of cases, while mesenteric ischaemia (MI) and Crohn’ disease (CD) were the main underlying diseases. IVS dependency was longer than 3 years in around 50% of cases; IVS was infused ≥5 days/week in 75% and FE in 10% of cases. Within the SBS-IF cohort: CD was twice and thrice more frequent in SBS-J than SBS-JC and SBS-JIC, respectively, while MI was more frequent in SBS-JC and SBS-JIC. Within countries: SBS-J represented 75% or more of patients in UK and Denmark and 50-60% in the other countries, except Poland where SBS-JC prevailed. CD was the main underlying disease in UK, USA, Denmark and The Netherlands, while MI prevailed in France, Italy and Poland. Conclusions: SBS-IF type is primarily determined by the underlying disease, with significant variation between countries. These novel data will be useful for planning and managing both clinical activity and research studies on SBS.
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| 5. |
- Újvári, Gábor, et al.
(author)
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Coupled European and Greenland last glacial dust activity driven by North Atlantic climate
- 2017
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In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:50, s. E10632-E10638
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Journal article (peer-reviewed)abstract
- Centennial-scale mineral dust peaks in last glacial Greenland ice cores match the timing of lowest Greenland temperatures, yet little is known of equivalent changes in dust-emitting regions, limiting our understanding of dust−climate interaction. Here, we present the most detailed and precise age model for European loess dust deposits to date, based on 125 accelerator mass spectrometry 14C ages from Dunaszekcső, Hungary. The record shows that variations in glacial dust deposition variability on centennial–millennial timescales in east central Europe and Greenland were synchronous within uncertainty. We suggest that precipitation and atmospheric circulation changes were likely the major influences on European glacial dust activity and propose that European dust emissions were modulated by dominant phases of the North Atlantic Oscillation, which had a major influence on vegetation and local climate of European dust source regions.
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