| 1. |
- Jones, Robert P., et al.
(författare)
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Patterns of Recurrence After Resection of Pancreatic Ductal Adenocarcinoma : A Secondary Analysis of the ESPAC-4 Randomized Adjuvant Chemotherapy Trial
- 2019
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Ingår i: JAMA Surgery. - : AMER MEDICAL ASSOC. - 2168-6254 .- 2168-6262. ; 154:11, s. 1038-1048
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Tidskriftsartikel (refereegranskat)abstract
- Importance: The patterns of disease recurrence after resection of pancreatic ductal adenocarcinoma with adjuvant chemotherapy remain unclear.Objective: To define patterns of recurrence after adjuvant chemotherapy and the association with survival.Design, Setting, and Participants: Prospectively collected data from the phase 3 European Study Group for Pancreatic Cancer 4 adjuvant clinical trial, an international multicenter study. The study included 730 patients who had resection and adjuvant chemotherapy for pancreatic cancer. Data were analyzed between July 2017 and May 2019.Interventions: Randomization to adjuvant gemcitabine or gemcitabine plus capecitabine.Main Outcomes and Measures: Overall survival, recurrence, and sites of recurrence.Results: Of the 730 patients, median age was 65 years (range 37-81 years), 414 were men (57%), and 316 were women (43%). The median follow-up time from randomization was 43.2 months (95% CI, 39.7-45.5 months), with overall survival from time of surgery of 27.9 months (95% CI, 24.8-29.9 months) with gemcitabine and 30.2 months (95% CI, 25.8-33.5 months) with the combination (HR, 0.81; 95% CI, 0.68-0.98; P=.03). The 5-year survival estimates were 17.1% (95% CI, 11.6%-23.5%) and 28.0% (22.0%-34.3%), respectively. Recurrence occurred in 479 patients (65.6%); another 78 patients (10.7%) died without recurrence. Local recurrence occurred at a median of 11.63 months (95% CI, 10.05-12.19 months), significantly different from those with distant recurrence with a median of 9.49 months (95% CI, 8.44-10.71 months) (HR, 1.21; 95% CI, 1.01-1.45; P=.04). Following recurrence, the median survival was 9.36 months (95% CI, 8.08-10.48 months) for local recurrence and 8.94 months (95% CI, 7.82-11.17 months) with distant recurrence (HR, 0.89; 95% CI, 0.73-1.09; P=.27). The median overall survival of patients with distant-only recurrence (23.03 months; 95% CI, 19.55-25.85 months) or local with distant recurrence (23.82 months; 95% CI, 17.48-28.32 months) was not significantly different from those with only local recurrence (24.83 months; 95% CI, 22.96-27.63 months) (P=.85 and P=.35, respectively). Gemcitabine plus capecitabine had a 21% reduction of death following recurrence compared with monotherapy (HR, 0.79; 95% CI, 0.64-0.98; P=.03).Conclusions and Relevance: There were no significant differences between the time to recurrence and subsequent and overall survival between local and distant recurrence. Pancreatic cancer behaves as a systemic disease requiring effective systemic therapy after resection.Trial Registration: ClinicalTrials.gov identifier: NCT00058201, EudraCT 2007-004299-38, and ISRCTN 96397434. This secondary analysis of a randomized clinical trial investigates patterns of recurrence after adjuvant chemotherapy in pancreatic cancer and the association with survival.
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| 2. |
- Dussutour, Audrey, et al.
(författare)
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Speed-accuracy tradeoffs and the construction of transport netowrks
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- One of the key challenges in the study of networks is linking structure to function. For example, how do design requirements about the speed and accuracy with which information is transferred through a network determine its form? We show that different strains of the slime mould Physarum polycephalum form different network structures, ranging from a diffuse network of thin links to a tree-like branching structure. Using a current-reinforced random walk model, we explain these different structures in terms of two model parameters: the strength and the degree of non-linearity in the reinforcement. These parameters are further shown to tune the speed and accuracy with which the network can detect resource gradients. We use a battery of experimental tests to show that Physarum strains with diffuse networks make more accurate but slower decisions and those with thick, trunk branches make faster less accurate decisions. Intermediate structures can also be found which are relatively fast and accurate. The current reinforced random walk employed by the slime mould provides a tunable algorithm for decision-making, which may also apply in other systems where transport networks are constructed.
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| 3. |
- Sumpter, Lovisa, et al.
(författare)
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Ethics as part of mathematical reasoning in sharing
- 2023
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Ingår i: Prometeica. - : Universidade Federal de Sao Paulo. - 1852-9488. ; :27, s. 649-657
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Tidskriftsartikel (refereegranskat)abstract
- There is a greater need in today's society, to understand and critically discuss how the limited resources of our planet are allocated. Often, mathematical models are used in connection with resource allocation problems, and a common view is that mathematics in itself is neutral. In this article, we challenge this view of mathematics as a neutral practice through an analysis of possible solutions to a sharing task. The tasks come from a research project aiming to study how mathematics can support ethical reasoning and ethical arguments can support different mathematical solutions when sharing a resource. In ethical reasoning, three components are addressed: Information, Coherence, and Engagement. We show that ethical reasoning is part of mathematical reasoning in all the solutions to the task, independent of whether the dividend is treated as indivisible or divisible.
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| 4. |
- Sumpter, Lovisa, et al.
(författare)
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How long will it take to have a 60/40 balance in mathematics in mathematics PhD education in Sweden?
- 2016
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Ingår i: Proceedings of the 40th Conference of the International Group for the Psychology of Mathematics Education. - : International Group for the Psychology of Mathematics Education. - 9781365463457 ; , s. 251-258
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Konferensbidrag (refereegranskat)abstract
- We investigate female participation in PhD education in mathematics. Nine of eleven subject areas for PhD studies in Sweden had reached a 60/40 gender balance in 2010, the exceptions being mathematics and engineering and technology. Using linear regression, we fit a growth model to the increase in the proportion of female PhD students. We show that mathematics has a slower growth rate in female participation than other subjects, and present differences can’t be attributed simply to a lower initial female participation. If current trends continue, it will take approximately another 15 years for mathematics to reach a 60/40 gender balance.
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| 5. |
- Sumpter, Lovisa, 1974-, et al.
(författare)
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La ética como parte del razonamiento matemático en el compartir
- 2023
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Ingår i: Prometeica. - 1852-9488. ; :27, s. 649-657
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Tidskriftsartikel (refereegranskat)abstract
- There is a greater need in today's society, to understand and critically discuss how the limited resources of our planet are allocated. Often, mathematical models are used in connection with resource allocation problems, and a common view is that mathematics in itself is neutral. In this article, we challenge this view of mathematics as a neutral practice through an analysis of possible solutions to a sharing task. The tasks come from a research project aiming to study how mathematics can support ethical reasoning and ethical arguments can support different mathematical solutions when sharing a resource. In ethical reasoning, three components are addressed: Information, Coherence, and Engagement. We show that ethical reasoning is part of mathematical reasoning in all the solutions to the task, independent of whether the dividend is treated as indivisible or divisible.
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| 6. |
- Sumpter, Lovisa, et al.
(författare)
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Sharing Four Biscuits Between Three People: An Illustrative Example of How Mathematics is Intertwined with Human Values
- 2024
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Ingår i: Journal of Humanistic Mathematics. - : Claremont Colleges Library. - 2159-8118. ; 14:1, s. 74-93
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Tidskriftsartikel (refereegranskat)abstract
- Despite convincing arguments by mathematicians, philosophers, sociologists and machine learning practitioners to the contrary, there remains a widespread no- tion amongst many members of the general public (and some practitioners) that mathematics is neutral, that it is free from human values. One reason why this notion persists is that we lack clear-cut examples that demonstrate how math- ematics and values are intertwined. In this paper, we offer one such example. In particular, we show that when sharing four biscuits between three people, several possible mathematical and ethical frameworks can be used. We demon- strate that different solutions—hiding one biscuit, arbitrarily sharing the extra biscuit, randomizing allocation, dividing the extra biscuit into three parts, and successively dividing it into smaller and smaller parts—involve different mathe- matical methods and evoke different human values. We discuss the construction of quantum biscuit splitting devices and the use of machine learning to divide biscuits. We argue that the multitude of different mathematically-correct so- lutions to this problem (each with its own ethical justification) might influence the values held by practicing mathematicians. The example we propose here has been used in teaching to help students understand why mathematics cannot be cleanly separated from human values.
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| 7. |
- Sumpter, Lovisa, et al.
(författare)
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Understanding Segregation : Upper Secondary School Student’s Work with the Schelling Model
- 2019
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Ingår i: Proceedings of the Tenth International Mathematics Education and Society Conference.
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Konferensbidrag (refereegranskat)abstract
- There are few research studies focusing on how humans can better understand segregation using mathematical models. In this paper, we explore how upper secondary school students work with the Schelling model using a computer game that was purposely designed for this study. The students were then allowed to run the model themselves. The results show that it was difficult to anticipate the degree to which segregation is generated within the model. The students mainly gave two types of explanations for the results. The first one was based on human psychology and the other was based on the mathematical principle that underlie the utility function of the model. The results are discussed from a perspective that illustrates the complexity of the subject, rather than as a measure of the teaching intervention.
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| 8. |
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| 9. |
- Sumpter, Lovisa, 1974-, et al.
(författare)
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Upper secondary school students' gendered self-evaluation in mathematics
- 2022
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Ingår i: Twelfth Congress of the European Society for Research in Mathematics Education (CERME12). - : European Society for Research in Mathematics Education. ; , s. 1434-1441
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Konferensbidrag (refereegranskat)abstract
- Self-evaluation is considered one of the key concepts when trying to understand motivation, and it is gaining more interest especially when looking at the age span 15-18 years. Previous studies in self- evaluation and mathematics tend to use data from international large scales assessments, arriving with rather ambiguous conclusions, and smaller studies tend to use only one measure without control factors. The aim of this paper was to test the hypothesis that boys are more confident than girls in mathematics, while using Swedish as a control subject. A questionnaire was handed out to 399 upper secondary school students from different regions in Sweden, both vocational programmes and programmes preparing for further studies. Using both non-parametric analysis and linear regression, the results support the hypothesis. The relationship to the idea of confidence gap is discussed.
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| 10. |
- Tsvetkova, Milena, et al.
(författare)
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An experimental study of segregation mechanisms
- 2016
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Ingår i: EPJ DATA SCIENCE. - : Springer Science and Business Media LLC. - 2193-1127. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Segregation is widespread in all realms of human society. Several influential studies have argued that intolerance is not a prerequisite for a segregated society, and that segregation can arise even when people generally prefer diversity. We investigated this paradox experimentally, by letting groups of high-school students play four different real-time interactive games. Incentives for neighbor similarity produced segregation, but incentives for neighbor dissimilarity and neighborhood diversity prevented it. The participants continued to move while their game scores were below optimal, but their individual moves did not consistently take them to the best alternative position. These small differences between human and simulated agents produced different segregation patterns than previously predicted, thus challenging conclusions about segregation arising from these models.
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