Search

Abstract Electrons from a laser wakefield accelerator have a limited energy gain due to dephasing and are prone to emittance growth, causing a large divergence. In this paper, we experimentally show that adjusting the plasma density profile can address both issues. Shock-assisted ionisation injection is used to produce 100 MeV quasi-monoenergetic electron bunches in the primary part of the accelerator. Downstream from the accelerator, a second, independently tuneable density region is added, which can be used to either boost the energy of the electron bunches or as a plasma lens for significant divergence reduction. An additional energy gain of 25% and a 40% divergence reduction are obtained. Theoretical models validate the effects.

Several qualities influence the processability of textile staple fibers: inter-fiber cohesion being one of the most important properties. Although various methods to measure this property have been explored, there is no consensus on the optimal technique, and existing methods often require specialized machinery. This article introduces and evaluates a straightforward method that utilizes only a carding machine and a tensile tester, both standard equipment in yarn laboratories. The proposed cohesion test method involves preparing carded webs, cutting them into nine rectangles, and then subjecting these samples to tensile testing. The method was initially assessed for repeatability and the normalization of results. Further experiments varied the fiber material (cotton and polyester), fiber organization, direction of fiber hooks, and finishing treatments. Force curves and their gradients were analyzed, alongside video footage, to study inter-fiber interactions during testing. The results demonstrated that the new test method could differentiate between fiber materials, fiber organizations, and quantify the effects from finishing treatments. The cohesion force (CF) of CO fibers was 30 % of that of PES fibers; carding had a greater impact on CO fibers compared to PES fibers, and treatment with lubricant reduced the CF by up to 35 %. However, the weight and dimensions of the samples must be controlled to ensure repeatability. In conclusion, the developed inter-fiber cohesion test method offers a promising and accessible approach to analyzing inter-fiber interactions in staple fibers.

Between tradition and reform: Pedagogical essay topics at two Swedish teacher training seminars, 1915–1937. During the beginning of the twentieth century, a series of school reforms was carried out in Sweden. One concerned the education of elementary school teachers. In this article, we examine which knowledge and teaching ideals that was posed by some of those who had the task of putting this reform into practice. At the center are the nearly five hundred essay topics that were offered at the teacher training seminars in Lund (only male apprentices) and Falun (only female apprentices) 1914–1937. The results advocate that two rather different local cultures of knowledge were developed at the two seminars. While the essay topics that were offered in Lund mostly seems to promote a more traditional reproductive view on teaching, the ones proposed in Falun rather appears to encourage a much more reformistic understanding of schooling. Hence it is suggested that the latter might be understood as an aspiration to establish a more autonomous and independent women teacher identity.

Abstract Background Patients with type 2 diabetes have an increased risk of death and cardiovascular events and people with diabetes or prediabetes have been found to have increased atherosclerotic burden in the coronary and carotid arteries. This study will estimate the cross-sectional prevalence of atherosclerosis in the coronary and carotid arteries in individuals with prediabetes and diabetes, compared with normoglycaemic individuals in a large population-based cohort. Methods The 30,154 study participants, 50–64 years, were categorized according to their fasting glycaemic status or self-reported data as normoglycaemic, prediabetes, and previously undetected or known diabetes. Prevalence of affected coronary artery segments, severity of stenosis and coronary artery calcium score (CACS) were determined by coronary computed tomography angiography. Total atherosclerotic burden was assessed in the 11 clinically most relevant segments using the Segment Involvement Score and as the presence of any coronary atherosclerosis. The presence of atherosclerotic plaque in the carotid arteries was determined by ultrasound examination. Results Study participants with prediabetes (n = 4804, 16.0%) or diabetes (n = 2282, 7.6%) had greater coronary artery plaque burden, more coronary stenosis and higher CACS than normoglycaemic participants (all, p

At a time when society is characterised by a polarised social climate, it is teachers who need to contribute to a nuanced orientation of the world. This article looks at the ways historical narratives can be used as a collective didactic resource in the historical-cultural context of contemporary society. Its purpose is to analyse the didactic function that underlies historical narratives in relation to students’ understanding of society. Our study builds on three focus group interviews with five upper-secondary-school teachers of history and social studies. The method used is the stimulated-recall interview whereby teachers talk about various teaching situations. Four uses of historical narratives were identified, each with its own didactic function. The first is the use of the “challenging” narrative, the function of which is to disrupt and realign students’ understanding of society. The second is the use of the “engaging” narrative: its function is to involve and activate students in their present understanding of society. The third is the use of the “unifying” narrative, the function of which is to bridge contradictions within society. The fourth and final narrative is the “complementing” narrative, whose function it is to broaden and open students’ understanding of society. To address students in terms of their present understanding of society, teachers employ these four narratives as didactic resources. In such a way, these uses of historical narratives tie in with the teachers’ overall aim to contribute an alternative perspective to students’ current understanding of society. As such, the results reveal the general theoretical knowledge teachers have relating to their profession.

Objectives The aim included investigation of the associations between sedentary (SED), low-intensity physical activity (LIPA), moderate-to-vigorous intensity PA (MVPA) and the prevalence of subclinical atherosclerosis in both coronaries and carotids and the estimated difference in prevalence by theoretical reallocation of time in different PA behaviours.Design Cross-sectional.Setting Multisite study at university hospitals.Participants A total of 22 670 participants without cardiovascular disease (51% women, 57.4 years, SD 4.3) from the population-based Swedish CArdioPulmonary bioImage study were included. SED, LIPA and MVPA were assessed by hip-worn accelerometer.Primary and secondary outcomes Any and significant subclinical coronary atherosclerosis (CA), Coronary Artery Calcium Score (CACS) and carotid atherosclerosis (CarA) were derived from imaging data from coronary CT angiography and carotid ultrasound.Results High daily SED (>70% ≈10.5 hours/day) associated with a higher OR 1.44 (95% CI 1.09 to 1.91), for significant CA, and with lower OR 0.77 (95% CI 0.63 to 0.95), for significant CarA. High LIPA (>55% ≈8 hours/day) associated with lower OR for significant CA 0.70 (95% CI 0.51 to 0.96), and CACS, 0.71 (95% CI 0.51 to 0.97), but with higher OR for CarA 1.41 (95% CI 1.12 to 1.76). MVPA above reference level, >2% ≈20 min/day, associated with lower OR for significant CA (OR range 0.61–0.67), CACS (OR range 0.71–0.75) and CarA (OR range 0.72–0.79). Theoretical replacement of 30 min of SED into an equal amount of MVPA associated with lower OR for significant CA, especially in participants with high SED 0.84 (95% CI 0.76 to 0.96) or low MVPA 0.51 (0.36 to 0.73).Conclusions MVPA was associated with a lower risk for significant atherosclerosis in both coronaries and carotids, while the association varied in strength and direction for SED and LIPA, respectively. If causal, clinical implications include avoiding high levels of daily SED and low levels of MVPA to reduce the risk of developing significant subclinical atherosclerosis.

Background and purpose: Periprosthetic joint infection (PJI) is a feared complication of arthroplasty surgery. There is controversy as to whether PJI also correlates with increased mortality. Our aim was to investigate in a nationwide cohort if PJI is an independent risk factor for dying. Patients and methods: We performed a retrospective cohort study based on data from the Swedish Hip Arthroplasty Register (SHAR). All patients with a revision THA performed between 1998 and 2017 were included. The outcome is mortality; exposure is PJI according to SHAR. The control group was study participants who underwent aseptic revision. Confounders were age, sex, diagnosis, and comorbidity according to the Elixhauser index. The outcome was analyzed with a Cox proportional hazards model. Results: 4,943 PJI revisions and 12,529 non-infected revisions were included in the analysis. The median follow-up time was 4.1 years. In the PJI group, 1,972 patients died and in the control group, 4,512. The incidence rate ratio was 1.19 (95% confidence interval [CI] 1.13–1.25), the crude hazard ratio (HR) 1.19 (CI 1.13–1.25), and the adjusted HR 1.05 (CI 0.99–1.12) for the exposed versus the unexposed group. The strongest confounder was comorbidity. Conclusion: The increased mortality risk after revision due to PJI is mainly caused by the comorbidity of the patient, rather than by the infection itself.

Bäck et al. describe a motion tracking algorithm to measure the flow rate through the mitral valve (MV) and the left atrial appendage (LAA) from 4D-CT data. The developed algorithm provided accurate tracking of dynamic cardiac geometries resulting in similar flow rates at the MV and LAA to those measured by 4D flow MRI.

Abstract Background Lesion/tissue segmentation on digital medical images enables biomarker extraction, image-guided therapy delivery, treatment response measurement, and training/validation for developing artificial intelligence algorithms and workflows. To ensure data reproducibility, criteria for standardised segmentation are critical but currently unavailable. Methods A modified Delphi process initiated by the European Imaging Biomarker Alliance (EIBALL) of the European Society of Radiology (ESR) and the European Organisation for Research and Treatment of Cancer (EORTC) Imaging Group was undertaken. Three multidisciplinary task forces addressed modality and image acquisition, segmentation methodology itself, and standards and logistics. Devised survey questions were fed via a facilitator to expert participants. The 58 respondents to Round 1 were invited to participate in Rounds 2–4. Subsequent rounds were informed by responses of previous rounds. Results/conclusions Items with ≥ 75% consensus are considered a recommendation. These include system performance certification, thresholds for image signal-to-noise, contrast-to-noise and tumour-to-background ratios, spatial resolution, and artefact levels. Direct, iterative, and machine or deep learning reconstruction methods, use of a mixture of CE marked and verified research tools were agreed and use of specified reference standards and validation processes considered essential. Operator training and refreshment were considered mandatory for clinical trials and clinical research. Items with a 60–74% agreement require reporting (site-specific accreditation for clinical research, minimal pixel number within lesion segmented, use of post-reconstruction algorithms, operator training refreshment for clinical practice). Items with ≤ 60% agreement are outside current recommendations for segmentation (frequency of system performance tests, use of only CE-marked tools, board certification of operators, frequency of operator refresher training). Recommendations by anatomical area are also specified.

IntroductionAtrial fibrillation (AF) is associated with an increased risk of stroke, often caused by thrombi that form in the left atrium (LA), and especially in the left atrial appendage (LAA). The underlying mechanism is not fully understood but is thought to be related to stagnant blood flow, which might be present despite sinus rhythm. However, measuring blood flow and stasis in the LAA is challenging due to its small size and low velocities. We aimed to compare the blood flow and stasis in the left atrium of paroxysmal AF patients with controls using computational fluid dynamics (CFD) simulations.MethodsThe CFD simulations were based on time-resolved computed tomography including the patient-specific cardiac motion. The pipeline allowed for analysis of 21 patients with paroxysmal AF and 8 controls. Stasis was estimated by computing the blood residence time.Results and DiscussionResidence time was elevated in the AF group (p

In recent years, many academics as well as local actors have started to question the feasibility of a two-state solution for Israel and Palestine. Increased Israeli unilateralism, expansionism as well as weak Palestinian institutions have instead pointed toward a “one-state-reality” where Israel is in de facto control over all lands. This in turn reveals a paradox, where international policymakers, most prominently in the EU and the US, and international organizations like the UN, seem determined to insist on a two-state solution, even though all facts on the ground indicate a move away from such a vision where the egalitarian principles inherent in the two-state solution exists in constant tension with expansionist attempts to establish Israeli sovereignty also on Palestinian land. This article unpacks various visions for the future in Israel-Palestine, based on egalitarian principles on the one hand and expansionist ones on the other and display how they current co-exist in a very uneasy relationship. The over-arching aim of the article is to understand how the EU relates to this paradox. We do this in three steps; first we conduct a mapping of visions for solving the Israeli-Palestinian conflict according to either egalitarian or expansionist principles, where we find one- as well as two-state solutions; second, we conduct a historical analysis on EU positions with regards to the abovementioned principles for solving the conflict, related to other powerful international actors' visions; lastly, we move to an investigation of current developments captured through recent speeches, documents and semi-structured interviews with centrally placed EU staff. Our main conclusion is that even though the EU is determined to hold on to the two state-solution, it however lacks willingness and/or power-resources to push Israel in that direction. Our interviewees seem painfully aware of the lack of viability of the two-state-solution and hence welcome criticism which could push for more egalitarian tendencies in Israel by appealing to its democratic-self-image. Here the current spread of the apartheid narrative among international organizations and an increased international human rights rhetoric emphasizing equal rights for two peoples seem to have left the EU balancing on a tight-rope where they have to choose between standing by status quo, risking supporting ultra-nationalist Israeli sovereignty-aspirations, or criticizing those, instead exposing itself to accusations of antisemitism.

Cloud formations often obscure optical satellite-based monitoring of the Earth’s surface, thus limiting Earth observation (EO) activities such as land cover mapping, ocean color analysis, and cropland monitoring. The integration of machine learning (ML) methods within the remote sensing domain has significantly improved performance for a wide range of EO tasks, including cloud detection and filtering, but there is still much room for improvement. A key bottleneck is that ML methods typically depend on large amounts of annotated data for training, which are often difficult to come by in EO contexts. This is especially true when it comes to cloud optical thickness (COT) estimation. A reliable estimation of COT enables more fine-grained and application-dependent control compared to using pre-specified cloud categories, as is common practice. To alleviate the COT data scarcity problem, in this work, we propose a novel synthetic dataset for COT estimation, which we subsequently leverage for obtaining reliable and versatile cloud masks on real data. In our dataset, top-of-atmosphere radiances have been simulated for 12 of the spectral bands of the Multispectral Imagery (MSI) sensor onboard Sentinel-2 platforms. These data points have been simulated under consideration of different cloud types, COTs, and ground surface and atmospheric profiles. Extensive experimentation of training several ML models to predict COT from the measured reflectivity of the spectral bands demonstrates the usefulness of our proposed dataset. In particular, by thresholding COT estimates from our ML models, we show on two satellite image datasets (one that is publicly available, and one which we have collected and annotated) that reliable cloud masks can be obtained. The synthetic data, the newly collected real dataset, code and models have been made publicly available.

Much more than a single method: Professional conversations concerning controversial issues in the field of geography instruction. Research on controversial issues in education is extensive. Generally, the teacher has been examined, or advised, based on preconceived ideas of how the teaching should preferably be designed. Although those recommendations have varied, they have usually been characterized by instruction and method. However, this article does not address such predetermined models of action. As an alternative, the starting point is based on the perspective of the teaching professional and on data generated from teacher interviews. The aim of the article is to examine how the overall function of education emerges when teachers speak of their own experiences of teaching about controversial issues in geography in secondary school. The findings illustrate how the teachers, based on a number of circumstances, make use of four different approaches: deflecting, enlightening, challenging, and correcting. Hence, from the perspective of the teaching profession, work on controversial issues seems less understandable in terms of a single approach. Instead, each situation seems to require its own situated and subject-related considerations and professional reflections.

Tidigare studier av bedömning i historia och samhällskunskap i den svenska skolan har företrädelsevis handlat om vad lärare bedömer, eller vad elever presterar (Berg & Persson, 2020). I den här artikeln är syftet istället att undersöka hur olika förståelser av dessa båda skolämnens elev-emancipatoriska potential aktualiserar olika typer av ut­maningar och möjligheter i lärares bedömningsuppdrag. Datainsamlingen bygger på åtta timmeslånga intervjuer med lärare som undervisar på gymnasiet i ett mellansvenskt län. Diskussionen om vad som skapar förutsättningar för en ny generation att förstå och kanske förändra sin egen och andras situation framstår ofta som polemisk. Medan vissa betonat betydelsen av vilken (redan etablerad) kunskap som förmedlas (jfr Young, 2013), har andra framhållit värdet av att låta undervisningen utgå från den enskilde elevens eller samhällsgruppens unikt situerade intressen, frågor och behov (jfr t.ex. De Lissovoy, 2010; Tur Porres et al., 2014). I de åtta lärarsamtalen framträder denna avvägning mellan det på förhand givna och det situerade, emellertid i mindre grad som ett antingen/eller. I den lärarprofessionella bedömningspraktiken tycks avpassningen snarare ta dialektisk form i mötet mellan ämnesinnehåll och elev. Samme lärare kan både ge uttryck för anspråk som aktiverar utmaningar förknippade med förutsägbarhet, och rymma skildringar av en strävan att låta bedömningsprocessen bli så öppen som möjlig (jfr Biesta, 2009). Det sätt som eleven visar sig och träder fram i ämnet tycks sätta avtryck i, men är inte ensamt av­görande för, frågan om vad undervisningen ges för innehåll.

Abstract Optimisation and reproducibility of beams of protons accelerated from laser-solid interactions require accurate control of a wide set of variables, concerning both the laser pulse and the target. Among the former ones, the chirp and temporal shape of the pulse reaching the experimental area may vary because of spectral phase modulations acquired along the laser system and beam transport. Here, we present an experimental study where we investigate the influence of the laser pulse chirp on proton acceleration from ultrathin flat foils (10 and 100 nm thickness), while minimising any asymmetry in the pulse temporal shape. The results show a $$\pm 10\%$$ ± 10 % change in the maximum proton energy depending on the sign of the chirp. This effect is most noticeable from 10 nm-thick target foils, suggesting a chirp-dependent influence of relativistic transparency.

Abstract Structured solid targets are widely investigated to increase the energy absorption of high-power laser pulses so as to achieve efficient ion acceleration. Here we report the first experimental study of the maximum energy of proton beams accelerated from sub-micrometric foils perforated with holes of nanometric size. By showing the lack of energy enhancement in comparison to standard flat foils, our results suggest that the high contrast routinely achieved with a double plasma mirror does not prevent damaging of the nanostructures prior to the main interaction. Particle-in-cell simulations support that even a short scale length plasma, formed in the last hundreds of femtoseconds before the peak of an ultrashort laser pulse, fills the holes and hinders enhanced electron heating. Our findings reinforce the need for improved laser contrast, as well as for accurate control and diagnostics of on-target plasma formation.

Abstract An electron beam of very high energy (50–250 MeV) can potentially produce a more favourable radiotherapy dose distribution compared to a state-of-the-art photon based radiotherapy technique. To produce an electron beam of sufficiently high energy to allow for a long penetration depth (several cm), very large accelerating structures are needed when using conventional radio-frequency technology, which may not be possible due to economical or spatial constraints. In this paper, we show transport and focusing of laser wakefield accelerated electron beams with a maximum energy of 160 MeV using electromagnetic quadrupole magnets in a point-to-point imaging configuration, yielding a spatial uncertainty of less than 0.1 mm, a total charge variation below $$1 \%$$ 1 % and a focal spot of $$2.3 \times 2.6\;{\text {mm}}^2$$ 2.3 × 2.6 mm 2 . The electron beam was focused to control the depth dose distribution and to improve the dose conformality inside a phantom of cast acrylic slabs and radiochromic film. The phantom was irradiated from 36 different angles to obtain a dose distribution mimicking a stereotactic radiotherapy treatment, with a peak fractional dose of 2.72 Gy and a total maximum dose of 65 Gy. This was achieved with realistic constraints, including 23 cm of propagation through air before any dose deposition in the phantom.

Background The cardiovagal function can be assessed by quantification of respiratory sinus arrhythmia (RSA) during a deep breathing test. However, population studies of RSA and coronary atherosclerosis are lacking. This population‐based study examined the relationship between RSA during deep breathing and coronary atherosclerosis, assessed by coronary artery calcium score (CACS). Methods and Results SCAPIS (Swedish Cardiopulmonary Bioimage Study) randomly invited men and women aged 50 to 64 years from the general population. CACS was obtained from computed tomography scanning, and deep breathing tests were performed in 4654 individuals. Expiration–inspiration differences (E‐Is) of heart rates were calculated, and reduced RSA was defined as E‐I in the lowest decile of the population. The relationship between reduced RSA and CACS (CACS≥100 or CACS≥300) was calculated using multivariable‐adjusted logistic regression. The proportion of CACS≥100 was 24% in the lowest decile of E‐I and 12% in individuals with E‐I above the lowest decile (P

Abstract Background Our aim was to compare CT images from native, nephrographic and excretory phases using image quality criteria as well as the detection of positive pathological findings in CT Urography, to explore if the radiation burden to the younger group of patients or patients with negative outcomes can be reduced. Methods This is a retrospective study of 40 patients who underwent a CT Urography examination on a 192-slice dual source scanner. Image quality was assessed for four specific renal image criteria from the European guidelines, together with pathological assessment in three categories: renal, other abdominal, and incidental findings without clinical significance. Each phase was assessed individually by three radiologists with varying experience using a graded scale. Certainty scores were derived based on the graded assessments. Statistical analysis was performed using visual grading regression (VGR). The limit for significance was set at p = 0.05. Results For visual reproduction of the renal parenchyma and renal arteries, the image quality was judged better for the nephrogram phase (p

Abstract Observer-driven pattern recognition is the standard for interpretation of medical images. To achieve global parity in interpretation, semi-quantitative scoring systems have been developed based on observer assessments; these are widely used in scoring coronary artery disease, the arthritides and neurological conditions and for indicating the likelihood of malignancy. However, in an era of machine learning and artificial intelligence, it is increasingly desirable that we extract quantitative biomarkers from medical images that inform on disease detection, characterisation, monitoring and assessment of response to treatment. Quantitation has the potential to provide objective decision-support tools in the management pathway of patients. Despite this, the quantitative potential of imaging remains under-exploited because of variability of the measurement, lack of harmonised systems for data acquisition and analysis, and crucially, a paucity of evidence on how such quantitation potentially affects clinical decision-making and patient outcome. This article reviews the current evidence for the use of semi-quantitative and quantitative biomarkers in clinical settings at various stages of the disease pathway including diagnosis, staging and prognosis, as well as predicting and detecting treatment response. It critically appraises current practice and sets out recommendations for using imaging objectively to drive patient management decisions.

Additive manufacturing (AM) includes a series of techniques used to create products, in several different materials, such as metal, polymer or ceramics, with digital models. The main advantage of AM is that it allows the creation of complex structures, but AM promises several additional advantages including the possibility to manufacture on demand or replacing smaller worn parts by directly building on an existing piece. Therefore, the interest for and establishment of AM is rapidly expanding, which is positive, however it is important to be aware that new techniques may also result in new challenges regarding health and safety issues. Metals in blood and possible clinical effects due to metal exposure were investigated in AM operators at one of the first serial producing AM facilities in the world during two consecutive years with implementation of preventive measures in-between. As comparison, welders and office workers as control group were investigated. Health investigations comprised of surveys, lung function tests, antioxidant activity and vascular inflammation as well as renal- and hepatic function analysis. AM operators had significantly reduced nickel levels in blood (10.8 vs 6.2 nmol/L) as well as improved lung function (80 vs 92% of predicted) from year 1 to year 2. This is in line with previously published results displaying reduced exposure. Blood cobalt and nickel levels correlated with previously reported urinary levels, while blood chromium did not. Multivariate modelling showed that blood cobalt, antioxidant/inflammatory marker serum amyloid A1/serum paraoxonase/arylesterase 1 activity and the hepatic markers aspartate transaminase, alanine transaminase, and alkaline phosphatase were higher in AM operators compared to controls. The study show that the selected clinical analyses could function as a complement to metal analyses in biological fluids when investigating exposure-related health effects in AM operators. However, validation in larger cohorts is necessary before more definite conclusions could be drawn.

Bokanmeldelse av Anders Persson

Coloniser or Tourist?: Questions and Exercises in Swedish History Textbooks, 1927–2015. The history of History as a Swedish school subject has usually been based on two sources: curriculum plans and textbook narratives. Drawing upon more than 900 exercises that occur in 72 history textbooks published 1927–2015, this article primarily examines which different approaches to history that have been prearranged to the pupils during the second half of the last century. It is shown that a great majority of the exercises, throughout the whole period of time, prescribes a simple reproduction of unchallenged truths. It is also argued that both disciplinarian assignments and aesthetic tasks, seem to appear at least as often before, as after, the 1970s. Subsequently, especially in the 1990s, the exercises occasionally ask for the individual student’s own opinions - without demanding them to consider any historical circumstances. Accordingly it is argued that while the former category of exercises most often enjoin the distanced view of the uninvolved tourist, the latter rather instructs the pupil to embrace the coloniser’s self-centred perspective of the past.

Kesebolite-(Ce), ideal formula CeCa2Mn(AsO4)[SiO3]3, is a new mineral (IMA No. 2019-097) recovered from mine dumps at the Kesebol Mn-(Fe-Cu) deposit in Västra Götaland, Sweden. It occurs with rhodonite, baryte, quartz, calcite, talc, andradite, rhodochrosite, K-feldspar, hematite, gasparite-(Ce), chernovite-(Y) and ferriakasakaite-(Ce). It forms mostly euhedral crystals, with lengthwise striation. The mineral is dark grayish-brown to brown, translucent, with light brown streak. It is optically biaxial (+), with weak pleochroism, and ncalc = 1.74. H = 5–6 and VHN100 = 825. Fair cleavage is observed on {100}. The calculated density is 3.998(5) g·cm−3. Kesebolite-(Ce) is monoclinic, P21/c, with unit-cell parameters from X-ray single-crystal diffraction data: a = 6.7382(3), b = 13.0368(6), c = 12.0958(6) Å, β = 98.578(2)°, and V = 1050.66(9) Å3, with Z = 4. Strongest Bragg peaks in the X-ray powder pattern are: [I(%), d(Å) (hkl)] 100, 3.114 (20-2); 92, 2.924 (140); 84, 3.138 (041); 72, 2.908 (014); 57, 3.228 (210); 48, 2.856 (042); 48, 3.002 (132). The unique crystal structure was solved and refined to R1 = 4.6%. It consists of 6-periodic single silicate chains along (001); these are interconnected to infinite (010) strings of alternating, corner-sharing MnO6 and AsO4 polyhedra, altogether forming a trellis-like framework parallel to (100).