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2. Two decades of SVT ablation in Denmark: a trend towards higher age, more comorbidity, and less prior use of antiarrhythmic and rate-limiting pharmacotherapy—a nationwide registry-based Danish study

Author

Middelfart, Charlotte, Tønnesen, Jacob, Zörner, Christopher R., Da Riis-Vestergaard, Lise, Pham, Maria Hang Xuan, Pallisgaard, Jannik Langtved, Ruwald, Martin H., Rasmussen, Peter Vibe, Johannessen, Arne, Hansen, Jim, Worck, Rene, Gislason, Gunnar, and Hansen, Morten Lock

Published
2024
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3. 100 ancient genomes show repeated population turnovers in Neolithic Denmark

Author

Allentoft, Morten E, Sikora, Martin, Fischer, Anders, Sjögren, Karl-Göran, Ingason, Andrés, Macleod, Ruairidh, Rosengren, Anders, Schulz Paulsson, Bettina, Jørkov, Marie Louise Schjellerup, Novosolov, Maria, Stenderup, Jesper, Price, T Douglas, Fischer Mortensen, Morten, Nielsen, Anne Birgitte, Ulfeldt Hede, Mikkel, Sørensen, Lasse, Nielsen, Poul Otto, Rasmussen, Peter, Jensen, Theis Zetner Trolle, Refoyo-Martínez, Alba, Irving-Pease, Evan K, Barrie, William, Pearson, Alice, Sousa da Mota, Bárbara, Demeter, Fabrice, Henriksen, Rasmus A, Vimala, Tharsika, McColl, Hugh, Vaughn, Andrew, Vinner, Lasse, Renaud, Gabriel, Stern, Aaron, Johannsen, Niels Nørkjær, Ramsøe, Abigail Daisy, Schork, Andrew Joseph, Ruter, Anthony, Gotfredsen, Anne Birgitte, Henning Nielsen, Bjarne, Brinch Petersen, Erik, Kannegaard, Esben, Hansen, Jesper, Buck Pedersen, Kristoffer, Pedersen, Lisbeth, Klassen, Lutz, Meldgaard, Morten, Johansen, Morten, Uldum, Otto Christian, Lotz, Per, Lysdahl, Per, Bangsgaard, Pernille, Petersen, Peter Vang, Maring, Rikke, Iversen, Rune, Wåhlin, Sidsel, Anker Sørensen, Søren, Andersen, Søren H, Jørgensen, Thomas, Lynnerup, Niels, Lawson, Daniel J, Rasmussen, Simon, Korneliussen, Thorfinn Sand, Kjær, Kurt H, Durbin, Richard, Nielsen, Rasmus, Delaneau, Olivier, Werge, Thomas, Kristiansen, Kristian, and Willerslev, Eske

Subjects
Biological Sciences, Genetics, History, Heritage and Archaeology, Human Society, Archaeology, Historical Studies, Anthropology, Humans, Genomics, Genotype, Denmark, Emigrants and Immigrants, Scandinavians and Nordic People, General Science & Technology
Abstract

Major migration events in Holocene Eurasia have been characterized genetically at broad regional scales1-4. However, insights into the population dynamics in the contact zones are hampered by a lack of ancient genomic data sampled at high spatiotemporal resolution5-7. Here, to address this, we analysed shotgun-sequenced genomes from 100 skeletons spanning 7,300 years of the Mesolithic period, Neolithic period and Early Bronze Age in Denmark and integrated these with proxies for diet (13C and 15N content), mobility (87Sr/86Sr ratio) and vegetation cover (pollen). We observe that Danish Mesolithic individuals of the Maglemose, Kongemose and Ertebølle cultures form a distinct genetic cluster related to other Western European hunter-gatherers. Despite shifts in material culture they displayed genetic homogeneity from around 10,500 to 5,900 calibrated years before present, when Neolithic farmers with Anatolian-derived ancestry arrived. Although the Neolithic transition was delayed by more than a millennium relative to Central Europe, it was very abrupt and resulted in a population turnover with limited genetic contribution from local hunter-gatherers. The succeeding Neolithic population, associated with the Funnel Beaker culture, persisted for only about 1,000 years before immigrants with eastern Steppe-derived ancestry arrived. This second and equally rapid population replacement gave rise to the Single Grave culture with an ancestry profile more similar to present-day Danes. In our multiproxy dataset, these major demographic events are manifested as parallel shifts in genotype, phenotype, diet and land use.

Published
2024

4. Population genomics of post-glacial western Eurasia

Author

Allentoft, Morten E, Sikora, Martin, Refoyo-Martínez, Alba, Irving-Pease, Evan K, Fischer, Anders, Barrie, William, Ingason, Andrés, Stenderup, Jesper, Sjögren, Karl-Göran, Pearson, Alice, Sousa da Mota, Bárbara, Schulz Paulsson, Bettina, Halgren, Alma, Macleod, Ruairidh, Jørkov, Marie Louise Schjellerup, Demeter, Fabrice, Sørensen, Lasse, Nielsen, Poul Otto, Henriksen, Rasmus A, Vimala, Tharsika, McColl, Hugh, Margaryan, Ashot, Ilardo, Melissa, Vaughn, Andrew, Fischer Mortensen, Morten, Nielsen, Anne Birgitte, Ulfeldt Hede, Mikkel, Johannsen, Niels Nørkjær, Rasmussen, Peter, Vinner, Lasse, Renaud, Gabriel, Stern, Aaron, Jensen, Theis Zetner Trolle, Scorrano, Gabriele, Schroeder, Hannes, Lysdahl, Per, Ramsøe, Abigail Daisy, Skorobogatov, Andrei, Schork, Andrew Joseph, Rosengren, Anders, Ruter, Anthony, Outram, Alan, Timoshenko, Aleksey A, Buzhilova, Alexandra, Coppa, Alfredo, Zubova, Alisa, Silva, Ana Maria, Hansen, Anders J, Gromov, Andrey, Logvin, Andrey, Gotfredsen, Anne Birgitte, Henning Nielsen, Bjarne, González-Rabanal, Borja, Lalueza-Fox, Carles, McKenzie, Catriona J, Gaunitz, Charleen, Blasco, Concepción, Liesau, Corina, Martinez-Labarga, Cristina, Pozdnyakov, Dmitri V, Cuenca-Solana, David, Lordkipanidze, David O, En’shin, Dmitri, Salazar-García, Domingo C, Price, T Douglas, Borić, Dušan, Kostyleva, Elena, Veselovskaya, Elizaveta V, Usmanova, Emma R, Cappellini, Enrico, Brinch Petersen, Erik, Kannegaard, Esben, Radina, Francesca, Eylem Yediay, Fulya, Duday, Henri, Gutiérrez-Zugasti, Igor, Merts, Ilya, Potekhina, Inna, Shevnina, Irina, Altinkaya, Isin, Guilaine, Jean, Hansen, Jesper, Aura Tortosa, Joan Emili, Zilhão, João, Vega, Jorge, Buck Pedersen, Kristoffer, Tunia, Krzysztof, Zhao, Lei, Mylnikova, Liudmila N, Larsson, Lars, Metz, Laure, Yepiskoposyan, Levon, Pedersen, Lisbeth, Sarti, Lucia, Orlando, Ludovic, Slimak, Ludovic, Klassen, Lutz, Blank, Malou, González-Morales, Manuel, and Silvestrini, Mara

Subjects
Biological Sciences, Genetics, History, Heritage and Archaeology, Human Society, Historical Studies, Anthropology, Biotechnology, Humans, Genomics, Diploidy, Agriculture, Europe, Metagenomics, General Science & Technology
Abstract

Western Eurasia witnessed several large-scale human migrations during the Holocene1-5. Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes-mainly from the Mesolithic and Neolithic periods-from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a 'great divide' genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 BP, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 BP, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a 'Neolithic steppe' cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations.

Published
2024

12. Optimal Decremental Connectivity in Non-Sparse Graphs

Author

Aaman, Anders, Karczmarz, Adam, Łącki, Jakub, Parotsidis, Nikos, Rasmussen, Peter M. R., and Thorup, Mikkel

Subjects
Computer Science - Data Structures and Algorithms
Abstract

We present a dynamic algorithm for maintaining the connected and 2-edge-connected components in an undirected graph subject to edge deletions. The algorithm is Monte-Carlo randomized and processes any sequence of edge deletions in $O(m + n \operatorname{polylog} n)$ total time. Interspersed with the deletions, it can answer queries to whether any two given vertices currently belong to the same (2-edge-)connected component in constant time. Our result is based on a general Monte-Carlo randomized reduction from decremental $c$-edge-connectivity to a variant of fully-dynamic $c$-edge-connectivity on a sparse graph. While being Monte-Carlo, our reduction supports a certain final self-check that can be used in Las Vegas algorithms for static problems such as Unique Perfect Matching. For non-sparse graphs with $\Omega(n \operatorname{polylog} n)$ edges, our connectivity and $2$-edge-connectivity algorithms handle all deletions in optimal linear total time, using existing algorithms for the respective fully-dynamic problems. This improves upon an $O(m \log (n^2 / m) + n \operatorname{polylog} n)$-time algorithm of Thorup [J.Alg. 1999], which runs in linear time only for graphs with $\Omega(n^2)$ edges. Our constant amortized cost for edge deletions in decremental connectivity in non-sparse graphs should be contrasted with an $\Omega(\log n/\log\log n)$ worst-case time lower bound in the decremental setting [Alstrup, Thore Husfeldt, FOCS'98] as well as an $\Omega(\log n)$ amortized time lower-bound in the fully-dynamic setting [Patrascu and Demaine STOC'04].

Published
2021

17. Stopping Rules for Algebraic Iterative Reconstruction Methods in Computed Tomography

Author

Hansen, Per Christian, Jørgensen, Jakob Sauer, and Rasmussen, Peter Winkel

Subjects
Mathematics - Numerical Analysis, Mathematics - Optimization and Control, 65F10, 65F22, 15A29
Abstract

Algebraic models for the reconstruction problem in X-ray computed tomography (CT) provide a flexible framework that applies to many measurement geometries. For large-scale problems we need to use iterative solvers, and we need stopping rules for these methods that terminate the iterations when we have computed a satisfactory reconstruction that balances the reconstruction error and the influence of noise from the measurements. Many such stopping rules are developed in the inverse problems communities, but they have not attained much attention in the CT world. The goal of this paper is to describe and illustrate four stopping rules that are relevant for CT reconstructions., Comment: 11 pages, 10 figures

Published
2021

22. Tiling with Squares and Packing Dominos in Polynomial Time

Author

Aamand, Anders, Abrahamsen, Mikkel, Ahle, Thomas D., and Rasmussen, Peter M. R.

Subjects
Computer Science - Computational Geometry, Computer Science - Data Structures and Algorithms
Abstract

A polyomino is a polygonal region with axis parallel edges and corners of integral coordinates, which may have holes. In this paper, we consider planar tiling and packing problems with polyomino pieces and a polyomino container $P$. We give two polynomial time algorithms, one for deciding if $P$ can be tiled with $k\times k$ squares for any fixed $k$ which can be part of the input (that is, deciding if $P$ is the union of a set of non-overlapping $k\times k$ squares) and one for packing $P$ with a maximum number of non-overlapping and axis-parallel $2\times 1$ dominos, allowing rotations by $90^\circ$. As packing is more general than tiling, the latter algorithm can also be used to decide if $P$ can be tiled by $2\times 1$ dominos. These are classical problems with important applications in VLSI design, and the related problem of finding a maximum packing of $2\times 2$ squares is known to be NP-Hard [J. Algorithms 1990]. For our three problems there are known pseudo-polynomial time algorithms, that is, algorithms with running times polynomial in the area of $P$. However, the standard, compact way to represent a polygon is by listing the coordinates of the corners in binary. We use this representation, and thus present the first polynomial time algorithms for the problems. Concretely, we give a simple $O(n\log n)$ algorithm for tiling with squares, and a more involved $O(n^3\,\text{polylog}\, n)$ algorithm for packing and tiling with dominos, where $n$ is the number of corners of $P$., Comment: Compared to the first version, running times for domino packing have been improved and a simpler algorithm has been described

Published
2020

23. Support of Closed Walks and Second Eigenvalue Multiplicity of the Normalized Adjacency Matrix

Author

McKenzie, Theo, Rasmussen, Peter M. R., and Srivastava, Nikhil

Subjects
Mathematics - Combinatorics, Computer Science - Discrete Mathematics, Mathematics - Metric Geometry, Mathematics - Probability, Mathematics - Spectral Theory
Abstract

We show that the multiplicity of the second normalized adjacency matrix eigenvalue of any connected graph of maximum degree $\Delta$ is bounded by $O(n \Delta^{7/5}/\log^{1/5-o(1)}n)$ for any $\Delta$, and by $O(n\log^{1/2}d/\log^{1/4-o(1)}n)$ for simple $d$-regular graphs when $d\ge \log^{1/4}n$. In fact, the same bounds hold for the number of eigenvalues in any interval of width $\lambda_2/\log_\Delta^{1-o(1)}n$ containing the second eigenvalue $\lambda_2$. The main ingredient in the proof is a polynomial (in $k$) lower bound on the typical support of a closed random walk of length $2k$ in any connected graph, which in turn relies on new lower bounds for the entries of the Perron eigenvector of submatrices of the normalized adjacency matrix., Comment: A previous version of this paper proved the main result for d-regular graphs. The current version proves a more general result for the normalized adjacency matrix of bounded degree graphs. New version fixes an incorrect citation in the proof of Proposition 5.2. 24pp, 3 figures

Published
2020

24. No Repetition: Fast Streaming with Highly Concentrated Hashing

Author

Aamand, Anders, Das, Debarati, Kipouridis, Evangelos, Knudsen, Jakob B. T., Rasmussen, Peter M. R., and Thorup, Mikkel

Subjects
Computer Science - Data Structures and Algorithms
Abstract

To get estimators that work within a certain error bound with high probability, a common strategy is to design one that works with constant probability, and then boost the probability using independent repetitions. Important examples of this approach are small space algorithms for estimating the number of distinct elements in a stream, or estimating the set similarity between large sets. Using standard strongly universal hashing to process each element, we get a sketch based estimator where the probability of a too large error is, say, 1/4. By performing $r$ independent repetitions and taking the median of the estimators, the error probability falls exponentially in $r$. However, running $r$ independent experiments increases the processing time by a factor $r$. Here we make the point that if we have a hash function with strong concentration bounds, then we get the same high probability bounds without any need for repetitions. Instead of $r$ independent sketches, we have a single sketch that is $r$ times bigger, so the total space is the same. However, we only apply a single hash function, so we save a factor $r$ in time, and the overall algorithms just get simpler. Fast practical hash functions with strong concentration bounds were recently proposed by Aamand em et al. (to appear in STOC 2020). Using their hashing schemes, the algorithms thus become very fast and practical, suitable for online processing of high volume data streams., Comment: 10 pages

Published
2020

26. Publisher Correction: Population genomics of post-glacial western Eurasia

Author

Allentoft, Morten E., Sikora, Martin, Refoyo-Martínez, Alba, Irving-Pease, Evan K., Fischer, Anders, Barrie, William, Ingason, Andrés, Stenderup, Jesper, Sjögren, Karl-Göran, Pearson, Alice, Sousa da Mota, Bárbara, Schulz Paulsson, Bettina, Halgren, Alma, Macleod, Ruairidh, Jørkov, Marie Louise Schjellerup, Demeter, Fabrice, Sørensen, Lasse, Nielsen, Poul Otto, Henriksen, Rasmus A., Vimala, Tharsika, McColl, Hugh, Margaryan, Ashot, Ilardo, Melissa, Vaughn, Andrew, Fischer Mortensen, Morten, Nielsen, Anne Birgitte, Ulfeldt Hede, Mikkel, Johannsen, Niels Nørkjær, Rasmussen, Peter, Vinner, Lasse, Renaud, Gabriel, Stern, Aaron, Jensen, Theis Zetner Trolle, Scorrano, Gabriele, Schroeder, Hannes, Lysdahl, Per, Ramsøe, Abigail Daisy, Skorobogatov, Andrei, Schork, Andrew Joseph, Rosengren, Anders, Ruter, Anthony, Outram, Alan, Timoshenko, Aleksey A., Buzhilova, Alexandra, Coppa, Alfredo, Zubova, Alisa, Silva, Ana Maria, Hansen, Anders J., Gromov, Andrey, Logvin, Andrey, Gotfredsen, Anne Birgitte, Henning Nielsen, Bjarne, González-Rabanal, Borja, Lalueza-Fox, Carles, McKenzie, Catriona J., Gaunitz, Charleen, Blasco, Concepción, Liesau, Corina, Martinez-Labarga, Cristina, Pozdnyakov, Dmitri V., Cuenca-Solana, David, Lordkipanidze, David O., En’shin, Dmitri, Salazar-García, Domingo C., Price, T. Douglas, Borić, Dušan, Kostyleva, Elena, Veselovskaya, Elizaveta V., Usmanova, Emma R., Cappellini, Enrico, Brinch Petersen, Erik, Kannegaard, Esben, Radina, Francesca, Eylem Yediay, Fulya, Duday, Henri, Gutiérrez-Zugasti, Igor, Merts, Ilya, Potekhina, Inna, Shevnina, Irina, Altinkaya, Isin, Guilaine, Jean, Hansen, Jesper, Aura Tortosa, Joan Emili, Zilhão, João, Vega, Jorge, Buck Pedersen, Kristoffer, Tunia, Krzysztof, Zhao, Lei, Mylnikova, Liudmila N., Larsson, Lars, Metz, Laure, Yepiskoposyan, Levon, Pedersen, Lisbeth, Sarti, Lucia, Orlando, Ludovic, Slimak, Ludovic, Klassen, Lutz, Blank, Malou, González-Morales, Manuel, Silvestrini, Mara, Vretemark, Maria, Nesterova, Marina S., Rykun, Marina, Rolfo, Mario Federico, Szmyt, Marzena, Przybyła, Marcin, Calattini, Mauro, Sablin, Mikhail, Dobisíková, Miluše, Meldgaard, Morten, Johansen, Morten, Berezina, Natalia, Card, Nick, Saveliev, Nikolai A., Poshekhonova, Olga, Rickards, Olga, Lozovskaya, Olga V., Gábor, Olivér, Uldum, Otto Christian, Aurino, Paola, Kosintsev, Pavel, Courtaud, Patrice, Ríos, Patricia, Mortensen, Peder, Lotz, Per, Persson, Per, Bangsgaard, Pernille, de Barros Damgaard, Peter, Vang Petersen, Peter, Martinez, Pilar Prieto, Włodarczak, Piotr, Smolyaninov, Roman V., Maring, Rikke, Menduiña, Roberto, Badalyan, Ruben, Iversen, Rune, Turin, Ruslan, Vasilyev, Sergey, Wåhlin, Sidsel, Borutskaya, Svetlana, Skochina, Svetlana, Sørensen, Søren Anker, Andersen, Søren H., Jørgensen, Thomas, Serikov, Yuri B., Molodin, Vyacheslav I., Smrcka, Vaclav, Merts, Victor, Appadurai, Vivek, Moiseyev, Vyacheslav, Magnusson, Yvonne, Kjær, Kurt H., Lynnerup, Niels, Lawson, Daniel J., Sudmant, Peter H., Rasmussen, Simon, Korneliussen, Thorfinn Sand, Durbin, Richard, Nielsen, Rasmus, Delaneau, Olivier, Werge, Thomas, Racimo, Fernando, Kristiansen, Kristian, and Willerslev, Eske

Published
2024
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27. Management of Atrial Fibrillation in Older Patients by Morbidity Burden: Insights From Get With The Guidelines‐Atrial Fibrillation

Author

Dalgaard, Frederik, Xu, Haolin, Matsouaka, Roland A, Russo, Andrea M, Curtis, Anne B, Rasmussen, Peter Vibe, Ruwald, Martin H, Fonarow, Gregg C, Lowenstern, Angela, Hansen, Morten L, Pallisgaard, Jannik L, Alexander, Karen P, Alexander, John H, Lopes, Renato D, Granger, Christopher B, Lewis, William R, Piccini, Jonathan P, and Al‐Khatib, Sana M

Subjects
Biomedical and Clinical Sciences, Cardiovascular Medicine and Haematology, Aging, Cardiovascular, Heart Disease, Clinical Research, Management of diseases and conditions, 7.1 Individual care needs, Administration, Oral, Age Factors, Aged, Aged, 80 and over, Anticoagulants, Atrial Fibrillation, Cross-Sectional Studies, Female, Hospitalization, Humans, Logistic Models, Male, Multimorbidity, Odds Ratio, Practice Guidelines as Topic, Practice Patterns, Physicians', Registries, anticoagulation, atrial fibrillation, comorbidities, multimorbidity, oral anticoagulants, prescription, quality of care, Cardiorespiratory Medicine and Haematology, Cardiovascular medicine and haematology
Abstract

Background Knowledge is scarce regarding how multimorbidity is associated with therapeutic decisions regarding oral anticoagulants (OACs) in patients with atrial fibrillation. Methods and Results We conducted a cross-sectional study of hospitalized patients with atrial fibrillation using the Get With The Guidelines-Atrial Fibrillation registry from 2013 to 2019. We identified patients ≥65 years and eligible for OAC therapy. Using 16 available comorbidity categories, patients were stratified by morbidity burden. A multivariable logistic regression model was used to determine the odds of receiving OAC prescription at discharge by morbidity burden. We included 34 174 patients with a median (interquartile range) age of 76 (71-83) years, 56.6% women, and 41.9% were not anticoagulated at admission. Of these patients, 38.6% had 0 to 2 comorbidities, 50.7% had 3 to 5 comorbidities, and 10.7% had ≥6 comorbidities. The overall discharge OAC prescription was high (85.6%). The prevalence of patients with multimorbidity increased from 59.7% in 2014 to 64.3% in 2019 (P trend=0.002). Using 0 to 2 comorbidities as the reference, the adjusted odds ratio (95% CI) of OAC prescription were 0.93 (0.82, 1.05) for patients with 3 to 5 comorbidities and 0.72 (0.60, 0.86) for patients with ≥6 comorbidities. In those with ≥6 comorbidities, the most common reason for nonprescription of OACs were frequent falls/frailty (31.0%). Conclusions In a contemporary quality-of-care database of hospitalized patients with atrial fibrillation eligible for OAC therapy, multimorbidity was common. A higher morbidity burden was associated with a lower odds of OAC prescription. This highlights the need for interventions to improve adherence to guideline-recommended anticoagulation in multimorbid patients with atrial fibrillation.

Published
2020

28. Fast hashing with Strong Concentration Bounds

Author

Aamand, Anders, Knudsen, Jakob B. T., Knudsen, Mathias B. T., Rasmussen, Peter M. R., and Thorup, Mikkel

Subjects
Computer Science - Data Structures and Algorithms
Abstract

Previous work on tabulation hashing by Patrascu and Thorup from STOC'11 on simple tabulation and from SODA'13 on twisted tabulation offered Chernoff-style concentration bounds on hash based sums, e.g., the number of balls/keys hashing to a given bin, but under some quite severe restrictions on the expected values of these sums. The basic idea in tabulation hashing is to view a key as consisting of $c=O(1)$ characters, e.g., a 64-bit key as $c=8$ characters of 8-bits. The character domain $\Sigma$ should be small enough that character tables of size $|\Sigma|$ fit in fast cache. The schemes then use $O(1)$ tables of this size, so the space of tabulation hashing is $O(|\Sigma|)$. However, the concentration bounds by Patrascu and Thorup only apply if the expected sums are $\ll |\Sigma|$. To see the problem, consider the very simple case where we use tabulation hashing to throw $n$ balls into $m$ bins and want to analyse the number of balls in a given bin. With their concentration bounds, we are fine if $n=m$, for then the expected value is $1$. However, if $m=2$, as when tossing $n$ unbiased coins, the expected value $n/2$ is $\gg |\Sigma|$ for large data sets, e.g., data sets that do not fit in fast cache. To handle expectations that go beyond the limits of our small space, we need a much more advanced analysis of simple tabulation, plus a new tabulation technique that we call \emph{tabulation-permutation} hashing which is at most twice as slow as simple tabulation. No other hashing scheme of comparable speed offers similar Chernoff-style concentration bounds., Comment: 54 pages, 3 figures. An extended abstract appeared at the 52nd Annual ACM Symposium on Theory of Computing (STOC20)

Published
2019

29. Classifying Convex Bodies by their Contact and Intersection Graphs

Author

Aamand, Anders, Abrahamsen, Mikkel, Knudsen, Jakob Bæk Tejs, and Rasmussen, Peter Michael Reichstein

Subjects
Computer Science - Computational Geometry, 52C05
Abstract

Suppose that $A$ is a convex body in the plane and that $A_1,\dots,A_n$ are translates of $A$. Such translates give rise to an intersection graph of $A$, $G=(V,E)$, with vertices $V=\{1,\dots,n\}$ and edges $E=\{uv\mid A_u\cap A_v\neq \emptyset\}$. The subgraph $G'=(V, E')$ satisfying that $E'\subset E$ is the set of edges $uv$ for which the interiors of $A_u$ and $A_v$ are disjoint is a unit distance graph of $A$. If furthermore $G'=G$, i.e., if the interiors of $A_u$ and $A_v$ are disjoint whenever $u\neq v$, then $G$ is a contact graph of $A$. In this paper we study which pairs of convex bodies have the same contact, unit distance, or intersection graphs. We say that two convex bodies $A$ and $B$ are equivalent if there exists a linear transformation $B'$ of $B$ such that for any slope, the longest line segments with that slope contained in $A$ and $B'$, respectively, are equally long. For a broad class of convex bodies, including all strictly convex bodies and linear transformations of regular polygons, we show that the contact graphs of $A$ and $B$ are the same if and only if $A$ and $B$ are equivalent. We prove the same statement for unit distance and intersection graphs., Comment: 19 pages, 7 figures

Published
2019

32. Stiffness Restricts the Stemness of the Intestinal Stem Cells and Skews Their Differentiation Toward Goblet Cells

Author

He, Shijie, Lei, Peng, Kang, Wenying, Cheung, Priscilla, Xu, Tao, Mana, Miyeko, Park, Chan Young, Wang, Hongyan, Imada, Shinya, Russell, Jacquelyn O., Wang, Jianxun, Wang, Ruizhi, Zhou, Ziheng, Chetal, Kashish, Stas, Eric, Mohad, Vidisha, Bruun-Rasmussen, Peter, Sadreyev, Ruslan I., Hodin, Richard A., Zhang, Yanhang, Breault, David T., Camargo, Fernando D., Yilmaz, Ömer H., Fredberg, Jeffrey J., and Saeidi, Nima

Published
2023
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33. Pivotal Trial of the Neuroform Atlas Stent for Treatment of Anterior Circulation Aneurysms

Author

Zaidat, Osama O, Hanel, Ricardo A, Sauvageau, Eric A, Aghaebrahim, Amin, Lin, Eugene, Jadhav, Ashutosh P, Jovin, Tudor G, Khaldi, Ahmad, Gupta, Rishi G, Johnson, Andrew, Frei, Donald, Loy, David, Malek, Adel, Toth, Gabor, Siddiqui, Adnan, Reavey-Cantwell, John, Thomas, Ajith, Hetts, Steven W, Jankowitz, Brian T, Gross, Bradley, Ducruet, Andrew, Panczkowski, David, Shoirah, Hazem, Al-Bayati, Alhamza, Weiner, Greg, Kenmuir, Cynthia, Tadi, Prasanna, Walker, Gregory, Johnson, K, Frei, Don, Bellon, Richard, Atchie, Benjamin, Kaminsky, Ian, Huddle, Dan, Bain, Mark, Rasmussen, Peter, Hussain, M Shazam, Moore, Nina, Masaryk, Thomas, Elgabaly, Mohamed, Cerejo, Russell, Hardman, Julian, John, Seby, Bauer, Andrew, Peih-Chir Tsai, Jenny, Levy, Elad, Snyder, Kenneth, Davies, Jason, Ogilvy, Christopher, Rivet, Dennis, Alexander, Michael, Moser, Franklin, Maya, Marcel, Schiraldi, Michael, Eboli, Paula, Caplan, Justin, Jiang, Bowen, Bender, Matthew, Colby, Geoffrey, Satti, Sudhakar, Sivapatham, Thinesh, Kung, David, Pukenas, Bryan, Hurst, Robert, Smith, Michelle J, Puri, Ajit, Massari, Francesco, Rex, David, Fraser, Justin, Grupke, Stephen, Alhajeri, Abdulnasser, Klucznik, Richard, Diaz, Orlando, Britz, Gavin, Zhan, Yi, Spiotta, Alejandro, Lena, Jonathan, Turk, Aquilla, Chaudry, Mohamad, Fargen, Kyle, Turner, Raymond, Kan, Peter, Duckworth, Edward, Asif Taqi, Muhammad, Hou, Samuel, Arthur, Adam S, Elijovich, Lucas, Hoit, Daniel, Nickele, Christopher, Vachhani, Jay, Thomas Doss, Vinodh, Crowley, Richard, Lopes, Demetrius, Chen, Michael, Hallam, Danial, Ghodke, Basavaraj, Kim, Louis, Callison, Richard, Alshekhlee, Amer, and Kale, Sushant

Subjects
Bioengineering, Stroke, Assistive Technology, Neurosciences, Clinical Research, Clinical Trials and Supportive Activities, Brain Disorders, Adult, Aged, Embolization, Therapeutic, Endovascular Procedures, Female, Humans, Intracranial Aneurysm, Male, Middle Aged, Stents, Treatment Outcome, angiography, intracranial aneurysm, middle cerebral artery, retreatment, stent, ATLAS Investigators, Cardiorespiratory Medicine and Haematology, Clinical Sciences, Neurology & Neurosurgery
Abstract

Background and purposeStent-assisted coil embolization using the new generation Neuroform Atlas Stent System has shown promising safety and efficacy. The primary study results of the anterior circulation aneurysm cohort of the treatment of wide-neck, saccular, intracranial, aneurysms with the Neuroform Atlas Stent System (ATLAS trial [Safety and Effectiveness of the Treatment of Wide Neck, Saccular Intracranial Aneurysms With the Neuroform Atlas Stent System]) are presented.MethodsATLAS IDE trial (Investigational Device Exemption) is a prospective, multicenter, single-arm, open-label study of wide-neck (neck ≥4 mm or dome-to-neck ratio 50%) at the target location. The primary safety end point was any major stroke or ipsilateral stroke or neurological death within 12 months. Adjudication of the primary end points was performed by an independent Imaging Core Laboratory and the Clinical Events Committee.ResultsA total of 182 patients with wide-neck anterior circulation aneurysms at 25 US centers were enrolled. The mean age was 60.3±11.4 years, 73.1% (133/182) women, and 80.8% (147/182) white. Mean aneurysm size was 6.1±2.2 mm, mean neck width was 4.1±1.2 mm, and mean dome-to-neck ratio was 1.2±0.3. The most frequent aneurysm locations were the anterior communicating artery (64/182, 35.2%), internal carotid artery ophthalmic artery segment (29/182, 15.9%), and middle cerebral artery bifurcation (27/182, 14.8%). Stents were placed in the anticipated anatomic location in all patients. The study met both primary safety and efficacy end points. The composite primary efficacy end point of complete aneurysm occlusion (Raymond-Roy 1) without parent artery stenosis or aneurysm retreatment was achieved in 84.7% (95% CI, 78.6%-90.9%) of patients. Overall, 4.4% (8/182, 95% CI, 1.9%-8.5%) of patients experienced a primary safety end point of major ipsilateral stroke or neurological death.ConclusionsIn the ATLAS IDE anterior circulation aneurysm cohort premarket approval study, the Neuroform Atlas stent with adjunctive coiling met the primary end points and demonstrated high rates of long-term complete aneurysm occlusion at 12 months, with 100% technical success and

Published
2020

39. Expander Graphs are Non-Malleable Codes

Author

Rasmussen, Peter M. R. and Sahai, Amit

Subjects
Computer Science - Cryptography and Security, Computer Science - Discrete Mathematics
Abstract

Any $d$-regular graph on $n$ vertices with spectral expansion $\lambda$ satisfying $n = \Omega(d^3\log(d)/\lambda)$ yields a $O\left(\frac{\lambda^{3/2}}{d}\right)$-non-malleable code for single-bit messages in the split-state model., Comment: 10 pages Resubmitted with revised introduction and acknowledgement

Published
2018

43. Combinatorial classification of quantum lens spaces

Author

Jensen, Peter Lunding, Klausen, Frederik Ravn, and Rasmussen, Peter M. R.

Subjects
Mathematics - Operator Algebras, Mathematics - Combinatorics, 46L35 (primary), 05C30 (secondary)
Abstract

We answer the question of how large the dimension of a quantum lens space must be, compared to the primary parameter $r$, for the isomorphism class to depend on the secondary parameters. Since classification results in C*-algebra theory reduces this question to one concerning a certain kind of $SL$-equivalence of integer matrices of a special form, our approach is entirely combinatorial and based on the counting of certain paths in the graphs shown by Hong and Szyma\'nski to describe the quantum lens spaces., Comment: 27 pages, 2 figures

Published
2017
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44. Cerebral blood flow regulation in hypobaric hypoxia: role of haemoconcentration.

Author

Turner, Rachel, Rasmussen, Peter, Gatterer, Hannes, Tremblay, Joshua C., Roche, Johanna, Strapazzon, Giacomo, Roveri, Giulia, Lawley, Justin, and Siebenmann, Christoph

Subjects
*BLOOD flow, *HYPOXEMIA, *BRAIN injuries, *HUMAN physiology, *HEMODYNAMICS
Abstract

During acute hypoxic exposure, cerebral blood flow (CBF) increases to compensate for the reduced arterial oxygen content (CaO2). Nevertheless, as exposure extends, both CaO2 and CBF progressively normalize. Haemoconcentration is the primary mechanism underlying the CaO2 restoration and may therefore explain, at least in part, the CBF normalization. Accordingly, we tested the hypothesis that reversing the haemoconcentration associated with extended hypoxic exposure returns CBF towards the values observed in acute hypoxia. Twenty‐three healthy lowlanders (12 females) completed two identical 4‐day sojourns in a hypobaric chamber, one in normoxia (NX) and one in hypobaric hypoxia (HH, 3500 m). CBF was measured by ultrasound after 1, 6, 12, 48 and 96 h and compared between sojourns to assess the time course of changes in CBF. In addition, CBF was measured at the end of the HH sojourn after hypervolaemic haemodilution. Compared with NX, CBF was increased in HH after 1 h (P = 0.001) but similar at all later time points (all P > 0.199). Haemoglobin concentration was higher in HH than NX from 12 h to 96 h (all P < 0.001). While haemodilution reduced haemoglobin concentration from 14.8 ± 1.0 to 13.9 ± 1.2 g·dl−1 (P < 0.001), it did not increase CBF (974 ± 282 to 872 ± 200 ml·min−1; P = 0.135). We thus conclude that, at least at this moderate altitude, haemoconcentration is not the primary mechanism underlying CBF normalization with acclimatization. These data ostensibly reflect the fact that CBF regulation at high altitude is a complex process that integrates physiological variables beyond CaO2. Key points: Acute hypoxia causes an increase in cerebral blood flow (CBF). However, as exposure extends, CBF progressively normalizes.We investigated whether hypoxia‐induced haemoconcentration contributes to the normalization of CBF during extended hypoxia.Following 4 days of hypobaric hypoxic exposure (corresponding to 3500 m altitude), we measured CBF before and after abolishing hypoxia‐induced haemoconcentration by hypervolaemic haemodilution.Contrary to our hypothesis, the haemodilution did not increase CBF in hypoxia.Our findings do not support haemoconcentration as a stimulus for the CBF normalization during extended hypoxia. [ABSTRACT FROM AUTHOR]

Published
2024
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45. Advancing physiology through transparency: Celebrating our first registered report.

Author

Rasmussen, Peter, Tipton, Michael J., Stewart, Alex, and Bailey, Damian M.

Subjects
*HIGH-intensity interval training, *SCHOLARSHIPS, *INTELLECTUAL property theft, *HUMAN physiology, *OPEN scholarship
Abstract

The article emphasizes the importance of transparency in scientific research, specifically focusing on the benefits of preregistration and registered reporting to enhance credibility and reproducibility. It discusses the value of separating hypothesis-testing and hypothesis-generating analyses, as well as the role of interdisciplinary collaborations in study design. The study also addresses common misconceptions about registered reports, highlighting their applicability across various disciplines and their contribution to improving research quality and credibility, particularly in the biomedical field. [Extracted from the article]

Published
2024
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47. Prognostic factors for disease activity in newly diagnosed teriflunomide-treated patients with multiple sclerosis: a nationwide Danish study.

Author

Mahler, Mie Reith, Magyari, Melinda, Pontieri, Luigi, Elberling, Frederik, Holm, Rolf Pringler, Weglewski, Arkadiusz, Poulsen, Mai Bang, Storr, Lars Kristian, Bekyarov, Plamen Anzhelov, Illes, Zsolt, Kant, Matthias, Sejbaek, Tobias, Stilund, Morten Leif, Rasmussen, Peter V., Brask, Maria, Urbonaviciute, Inga, and Sellebjerg, Finn

Subjects
MEDICAL sciences, SEX factors in disease, GENERAL Data Protection Regulation, 2016, PROPORTIONAL hazards models, PATIENT selection
Published
2024
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48. Disparities in the access to atrial fibrillation ablation in Denmark: who gets ablated, who neglected?

Author

Zörner, Christopher R, Tønnesen, Jacob, Riis-Vestergaard, Lise Da, Middelfart, Charlotte, Hein, Regitze, Rasmussen, Peter Vibe, Ruwald, Martin H, Gislason, Gunnar, and Hansen, Morten Lock

Abstract

Aims Atrial fibrillation (AF) is a common arrhythmia associated with reduced quality of life that can lead to serious complications such as stroke and heart failure. Ablation is a safe and effective treatment for AF but is not offered equally to all patients. The aim of this study is to identify demographic groups more or less likely to undergo AF ablation. Methods and results All patients with newly diagnosed AF between 2010 and 2018 were identified in the Danish nationwide registries. The association between gender, age, level of education and attachment to the job market, and the likelihood of receiving AF ablation was investigated using multivariable Cox proportional hazard analysis. Cumulative incidence was calculated using the Aalen–Johansen estimator. A total of 176 248 patients were included. Men were more likely to receive ablation than women (7% vs. 3%). Patients aged 25–44 and 45–64 were most likely to receive ablation, while only 0.7% of patients aged 80 or above received ablation. The rate of ablation significantly decreased with decreasing level of education. Full-time employed patients were most likely to receive ablation, followed by self-employed, unemployed, on sick leave, undergoing education, and early retired patients. Retired patients were the least likely to receive ablation (3%). Conclusion This study found that women, older patients, patients with lower levels of education, and patients on social benefits are less likely to receive AF ablation. These findings suggest that there are significant social and economic disparities in AF ablation treatment in Denmark. [ABSTRACT FROM AUTHOR]

Published
2024
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