The f-vector of the descent polytope

For a positive integer n and a subset S of [n-1], the descent polytope DP_S is the set of points x_1, ..., x_n in the n-dimensional unit cube [0,1]^n such that x_i >= x_{i+1} for i in S and x_i <= x_{i+1} otherwise. First, we express the f-vector of DP_S as a sum over all subsets of [n-1]. Second, we use certain factorizations of the associated word over a two-letter alphabet to describe the f-vector. We show that the f-vector is maximized when the set S is the alternating set {1,3,5, ...}. We derive a generating function for the f-polynomial F_S(t) of DP_S, written as a formal power series in two non-commuting variables with coefficients in Z[t]. We also obtain the generating function for the Ehrhart polynomials of the descent polytopes.Comment: 14 pages; to appear in Discrete & Computational Geometr

Cyclotomic factors of the descent set polynomial

We introduce the notion of the descent set polynomial as an alternative way of encoding the sizes of descent classes of permutations. Descent set polynomials exhibit interesting factorization patterns. We explore the question of when particular cyclotomic factors divide these polynomials. As an instance we deduce that the proportion of odd entries in the descent set statistics in the symmetric group S_n only depends on the number on 1's in the binary expansion of n. We observe similar properties for the signed descent set statistics.Comment: 21 pages, revised the proof of the opening result and cleaned up notatio

The evolution of handedness: why are ant colonies left- and right-handed?

No description supplie

Treatment Patterns and Use of Immune Checkpoint Inhibitors Among Patients with Metastatic Bladder Cancer in a Dutch Nationwide Cohort

Since 2017, two immune checkpoint inhibitors (ICIs) have become the standard of care for the treatment of metastatic urothelial carcinoma in Europe: pembrolizumab as second-line therapy and avelumab as maintenance therapy. Our aim was to describe the use of ICIs as first and later lines of treatment in patients with metastatic bladder cancer (mBC) in the Netherlands. We identified all patients diagnosed with primary mBC between 2018 and 2021 in the Netherlands from the Netherlands Cancer Registry (NCR). NCR data were supplemented with data from the Dutch nationwide Prospective Bladder Cancer Infrastructure (ProBCI) collected from medical files, with follow-up until death or end of data collection on January 1, 2023. A total of 1525 patients were diagnosed with primary mBC between 2018 and 2021 in the Netherlands. Of these, 34.7% received at least one line of systemic treatment with chemotherapy or ICI. After first-line platinum-based chemotherapy, 34.1% received second-line ICI and 3.9% received maintenance ICI. Among patients who completed or discontinued first-line cisplatin- or carboplatin-based chemotherapy after approval of maintenance ICI in the Netherlands, 40.7% and 19.7% received second-line ICI, and 9.3% and 14.1% received maintenance ICI, respectively. ICI use for mBC treatment has not increased considerably since their introduction in 2017. Future research should assess whether the introduction of maintenance avelumab (available since April 2021 in the Netherlands) has led to increases in the proportion of patients with mBC patients receiving systemic treatment and the proportion receiving ICI. Patient summary: We assessed the rate of immunotherapy use for patients with metastatic bladder cancer in the Netherlands. Since its introduction, immunotherapy has been used in a minority of patients, mostly as second-line treatment after platinum-based chemotherapy.</p

Advanced Automata Minimization

We present an efficient algorithm to reduce the size of nondeterministic Buchi word automata, while retaining their language. Additionally, we describe methods to solve PSPACE-complete automata problems like universality, equivalence and inclusion for much larger instances (1-3 orders of magnitude) than before. This can be used to scale up applications of automata in formal verification tools and decision procedures for logical theories. The algorithm is based on new transition pruning techniques. These use criteria based on combinations of backward and forward trace inclusions. Since these relations are themselves PSPACE-complete, we describe methods to compute good approximations of them in polynomial time. Extensive experiments show that the average-case complexity of our algorithm scales quadratically. The size reduction of the automata depends very much on the class of instances, but our algorithm consistently outperforms all previous techniques by a wide margin. We tested our algorithm on Buchi automata derived from LTL-formulae, many classes of random automata and automata derived from mutual exclusion protocols, and compared its performance to the well-known automata tool GOAL.Comment: 15 page

Affecting Effects on Affect: The Impact of Protocol Permutations on Affective Responses to Sprint Interval Exercise; A Systematic Review and Meta-Analysis of Pooled Individual Participant Data

Responses to sprint interval exercise (SIE) are hypothesized to be perceived as unpleasant, but SIE protocols are diverse, and moderating effects of various SIE protocol parameters on affective responses are unknown. We performed a systematic search to identify studies (up to 01/05/2021) measuring affective valence using the Feeling Scale during acute SIE in healthy adults. Thirteen studies involving 18 unique trials and 316 unique participant (142 women and 174 men) affective responses to SIE were eligible for inclusion. We received individual participant data for all participants from all studies. All available end-of-sprint affect scores from each trial were combined in a linear mixed model with sprint duration, mode, intensity, recovery duration, familiarization and baseline affect included as covariates. Affective valence decreased significantly and proportionally with each additional sprint repetition, but this effect was modified by sprint duration: affect decreased more during 30 s (0.84 units/sprint; 95% CI: 0.74–0.93) and 15–20 s sprints (1.02 units/sprint; 95% CI: 0.93–1.10) compared with 5–6 s sprints (0.20 units/sprint; 95% CI: 0.18–0.22) (both p < 0.0001). Although the difference between 15–20 s and 30 s sprints was also significant (p = 0.02), the effect size was trivial (d = −0.12). We observed significant but trivial effects of mode, sprint intensity and pre-trial familiarization, whilst there was no significant effect of recovery duration. We conclude that affective valence declines during SIE, but the magnitude of the decrease for an overall SIE session strongly depends on the number and duration of sprints. This information can be applied by researchers to design SIE protocols that are less likely to be perceived as unpleasant in studies of real-world effectiveness

Prospective bladder cancer infrastructure for experimental and observational research on bladder cancer: study protocol for the 'trials within cohorts' study ProBCI

INTRODUCTION: A better understanding of the molecular profile of bladder tumours, the identification of novel therapeutic targets, and introduction of new drugs and has renewed research interest in the field of bladder cancer. We describe the design and setup of a Dutch Prospective Bladder Cancer Infrastructure (ProBCI) as a means to stimulate and accelerate clinically meaningful experimental and observational research. METHODS AND ANALYSIS: ProBCI entails an open cohort of patients with bladder cancer in which the trials within cohorts (TwiCs) design can be embedded. Physicians in participating hospitals prospectively recruit invasive (≥T1) patients with bladder cancer on primary diagnosis for inclusion into the study. Extensive clinical data are collected and updated every 4 months, along with patient-reported outcomes and biomaterials. Informed consent includes participation in TwiCs studies and renewed contact for future studies. Consent for participation in questionnaires and molecular analyses that may yield incidental findings is optional. ETHICS AND DISSEMINATION: The Dutch ProBCI is a unique effort to construct a nation-wide cohort of patients with bladder cancer including clinical data, patient-reported outcomes and biomaterial, to facilitate observational and experimental research. Data and materials are available for other research groups on request through www.probci.nl. Ethics approval was obtained from METC Utrecht (reference: NL70207.041.19). TRIAL REGISTRATION NUMBER: NCT04503577

Visual feature binding in younger and older adults: Encoding and suffix interference effects

Three experiments investigated younger (18-25) and older (70-88) adults’ temporary memory for colour-shape combinations (binding). We focused upon estimating the magnitude of the binding cost for each age group across encoding time (Experiment 1; 900/1500ms), presentation format (Experiment 2; simultaneous/sequential), and interference (Experiment 3; control/suffix) conditions. In Experiment 1, encoding time did not differentially influence binding in the two age groups. In Experiment 2, younger adults exhibited poorer binding performance with sequential relative to simultaneous presentation, and serial position analyses highlighted a particular age-related difficulty remembering the middle item of a series (for all memory conditions). Experiments 1 to 3 demonstrated small to medium binding effect sizes in older adults across all encoding conditions, with binding less accurate than shape memory. However, younger adults also displayed negative effects of binding (small to large) in two of the experiments. Even when older adults exhibited a greater suffix interference effect in Experiment 3, this was for all memory types, not just binding. We therefore conclude that there is no consistent evidence for a visual binding deficit in healthy older adults. This relative preservation contrasts with the specific and substantial deficits in visual feature binding found in several recent studies of Alzheimer’s disease

Virulence factors of Actinobacillus pleuropneumoniae involved in colonization, persistence and induction of lesions in its porcine host

Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. The virulence factors of this microorganism involved in colonization and the induction of lung lesions have been thoroughly studied and some have been well characterized. A. pleuropneumoniae binds preferentially to cells of the lower respiratory tract in a process involving different adhesins and probably biofilm formation. Apx toxins and lipopolysaccharides exert pathogenic effects on several host cells, resulting in typical lung lesions. Lysis of host cells is essential for the bacterium to obtain nutrients from the environment and A. pleuropneumoniae has developed several uptake mechanisms for these nutrients. In addition to persistence in lung lesions, colonization of the upper respiratory tract – and of the tonsils in particular – may also be important for long-term persistent asymptomatic infection. Information on virulence factors involved in tonsillar and nasal cavity colonization and persistence is scarce, but it can be speculated that similar features as demonstrated for the lung may play a role

Pain relief in labour: a qualitative study to determine how to support women to make decisions about pain relief in labour

Background Engagement in decision making is a key priority of modern healthcare. Women are encouraged to make decisions about pain relief in labour in the ante-natal period based upon their expectations of what labour pain will be like. Many women find this planning difficult. The aim of this qualitative study was to explore how women can be better supported in preparing for, and making, decisions during pregnancy and labour regarding pain management. Methods Semi-structured interviews were conducted with 13 primiparous and 10 multiparous women at 36 weeks of pregnancy and again within six weeks postnatally. Data collection and analysis occurred concurrently to identify key themes. Results Three main themes emerged from the data. Firstly, during pregnancy women expressed a degree of uncertainty about the level of pain they would experience in labour and the effect of different methods of pain relief. Secondly, women reflected on how decisions had been made regarding pain management in labour and the degree to which they had felt comfortable making these decisions. Finally, women discussed their perceived levels of control, both desired and experienced, over both their bodies and the decisions they were making. Conclusion This study suggests that the current approach of antenatal preparation in the NHS, of asking women to make decisions antenatally for pain relief in labour, needs reviewing. It would be more beneficial to concentrate efforts on better informing women and on engaging them in discussions around their values, expectations and preferences and how these affect each specific choice rather than expecting them to make to make firm decisions in advance of such an unpredictable event as labour