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The SSRMP recommendations on reference dosimetry in kilovolt beams as used in radiation therapy were revised to establish current practice in Switzerland.The recommendations specify the dosimetry formalism, reference class dosimeter systems and conditions used for the calibration of low and medium energy x-ray beams. Practical guidance is provided on the determination of the beam quality specifier and all corrections required for converting instrument readings to absorbed dose to water. Guidance is also provided on the determination of relative dose under non-reference conditions and on the cross calibration of instruments.The effect of lack of electron equilibrium and influence of contaminant electrons when using thin window plane parallel chambers at x-ray tube potentials higher than 50 kV is elaborated in an appendix. In Switzerland the calibration of the reference system used for dosimetry is regulated by law. METAS and IRA are the authorities providing this calibration service to the radiotherapy departments. The last appendix of these recommendations summarise this calibration chain.

Background and Purpose: To improve radiotherapy (RT) planning efficiency and plan quality, knowledge-based planning (KBP) and deep learning (DL) solutions have been developed. We aimed to make a direct comparison of these models for breast cancer planning using the same training, validation, and testing sets. Materials and Methods: Two KBP models were trained and validated with 90 RT plans for left-sided breast cancer with 15 fractions of 2.6 Gy. The versions either used the full dataset (non-clean model) or a cleaned dataset (clean model), thus eliminating geometric and dosimetric outliers. Results were compared with a DL U-net model (previously trained and validated with the same 90 RT plans) and manually produced RT plans, for the same independent dataset of 15 patients. Clinically relevant dose volume histogram parameters were evaluated according to established consensus criteria. Results: Both KBP models underestimated the mean heart and lung dose equally 0.4 Gy (0.3–1.1 Gy) and 1.4 Gy (1.1–2.8 Gy) compared to the clinical plans 0.8 Gy (0.5–1.8 Gy) and 1.7 Gy (1.3–3.2 Gy) while in the final calculations the mean lung dose was higher 1.9–2.0 Gy (1.5–3.5 Gy) for both KPB models. The U-Net model resulted in a mean planning target volume dose of 40.7 Gy (40.4–41.3 Gy), slightly higher than the clinical plans 40.5 Gy (40.1–41.0 Gy). Conclusions: Only small differences were observed between the estimated and final dose calculation and the clinical results for both KPB models and the DL model. With a good set of breast plans, the data cleaning module is not needed and both KPB and DL models lead to clinically acceptable results.

IntroductionThis study aimed to identify and characterize novel siderophore-producing organisms capable of secreting high quantities of the iron-binding compounds. In the course of this, two not yet reported halophilic strains designated ATCHAT and ATCH28T were isolated from hypersaline, alkaline surface waters of Salar de Llamará and Laguna Lejía, respectively. The alkaline environment limits iron bioavailability, suggesting that native organisms produce abundant siderophores to sequester iron.MethodsBoth strains were characterized by polyphasic approach. Comparative analysis of the 16S rRNA gene sequences revealed their affiliation with the genus Halomonas. ATCHAT showed close similarity to Halomonas salicampi and Halomonas vilamensis, while ATCH28T was related closest to Halomonas ventosae and Halomonas salina. The ability of both strains to secrete siderophores was initially assessed using the chromeazurol S (CAS) liquid assay and subsequently further investigated through genomic analysis and NMR. Furthermore, the effect of various media components on the siderophore secretion by strain ATCH28T was explored.ResultsThe CAS assay confirmed the ability of both strains to produce iron-binding compounds. Genomic analysis of strain ATCHAT revealed the presence of a not yet reported NRPS-dependant gene cluster responsible for the secretion of siderophore. However, as only small amounts of siderophore were secreted, further investigations did not lie within the scope of this study. Via NMR and genomic analysis, strain ATCH28T has been determined to produce desferrioxamine E (DFOE). Although this siderophore is common in various terrestrial microorganisms, it has not yet been reported to occur within Halomonas, making strain ATCH28T the first member of the genus to produce a non-amphiphilic siderophore. By means of media optimization, the produced quantity of DFOE could be increased to more than 1000 µM.DiscussionPhenotypic and genotypic characteristics clearly differentiated both strains from other members of the genus Halomonas. Average nucleotide identity (ANI) values and DNA–DNA relatedness indicated that the strains represented two novel species. Therefore, both species should be added as new representatives of the genus Halomonas, for which the designations Halomonas llamarensis sp. nov. (type strain ATCHAT = DSM 114476 = LMG 32709) and Halomonas gemina sp. nov. (type strain ATCH28T = DSM 114418 = LMG 32708) are proposed.

Abstract Background Main purpose was to describe procedures and identify challenges in the implementation process of adaptive and non-adaptive MR-guided radiotherapy (MRgRT), especially new risks in workflow due to the new technique. We herein report the single center experience for the implementation of (MRgRT) and present an overview on our treatment practice. Methods Descriptive statistics were used to summarize clinical and technical characteristics of treatment and patient characteristics including sites treated between April 2019 and end of March 2020 after ethical approval. A risk analysis was performed to identify risks of the online adaptive workflow. Results A summary of the processes on the MR-Linac including workflows, quality assurance and possible pitfalls is presented. 111 patients with 124 courses were treated during the first year of MR-guided radiotherapy. The most commonly treated site was the abdomen (42% of all treatment courses). 73% of the courses were daily online adapted and a high number of treatment courses (75%) were treated with stereotactic body irradiation. Only 4/382 fractions could not be treated due to a failing online adaptive quality assurance. In the risk analysis for errors, the two risks with the highest risk priority number were both in the contouring category, making it the most critical step in the workflow. Conclusion Although challenging, establishment of MRgRT as a routinely used technique at our department was successful for all sites and daily o-ART was feasible from the first day on. However, ongoing research and reports will have to inform us on the optimal indications for MRgRT because careful patient selection is necessary as it continues to be a time-consuming treatment technique with restricted availability. After risk analysis, the most critical workflow category was the contouring process, which resembles the need of experienced staff and safety check paths.

In France, school directors are not the hierarchical superiors of their colleagues, all of whom have the status of school teacher. This article goes back to the historical origins of this situation under the Third Republic, a period of recon-figuration of the field of primary education and the power relations between school directors and assistant teachers. This study is based on data collected during an exhaustive study of a representative body of files of teachers be-longing to the first generation of public school teachers who entered primary education in the Seine between 1870 and 1886. The analysis of the conflictuality between teachers and school directors shows how the history of social relations in the field of primary education has produced the practical arrangements rejecting the reconstitution of a hierarchical subordination by the sedimentation of schemas of education perception of authority relations.

The complex formation of Eu(III) and Cm(III) was studied via tetradentate, hexadentate, and octadentate coordinating ligands of the aminopolycarboxylate family, viz., nitrilotriacetate (NTA3−), ethylenediaminetetraacetate (EDTA4−), and ethylene glycol-bis(2-aminoethyl ether)-N,N,N′,N′-tetraacetate (EGTA4−), respectively. Based on the complexones’ pKa values obtained from 1H nuclear magnetic resonance (NMR) spectroscopic pH titration, complex formation constants were determined by means of the parallel-factor-analysis-assisted evaluation of Eu(III) and Cm(III) time-resolved laser-induced fluorescence spectroscopy (TRLFS). This was complemented by isothermal titration calorimetry (ITC), providing the enthalpy and entropy of the complex formation. This allowed us to obtain genuine species along with their molecular structures and corresponding reliable thermodynamic data. The three investigated complexones formed 1:1 complexes with both Eu(III) and Cm(III). Besides the established Eu(III)–NTA 1:1 and 1:2 complexes, we observed, for the first time, the existence of a Eu(III)–NTA 2:2 complex of millimolar metal and ligand concentrations. Demonstrated for thermodynamic studies on Eu(III) and Cm(III) interaction with complexones, the utilized approach is commonly applicable to many other metal–ligand systems, even to high-affinity ligands.

Etidronic acid (1-Hydroxyethylidene-1,1-diphosphonic acid, HEDP, H4L) is a proposed decorporation agent for U(VI). This paper studied its complex formation with Eu(III), an inactive analog of trivalent actinides, over a wide pH range, at varying metal-to-ligand ratios (M:L) and total concentrations. Combining spectroscopic, spectrometric, and quantum chemical methods, five distinct Eu(III)−HEDP complexes were found, four of which were characterized. The readily soluble EuH2L+ and Eu(H2L)2− species with log β values of 23.7 ± 0.1 and 45.1 ± 0.9 are formed at acidic pH. At near-neutral pH, EuHL0s forms with a log β of ~23.6 and, additionally, a most probably polynuclear complex. The readily dissolved EuL− species with a log β of ~11.2 is formed at alkaline pH. A six-membered chelate ring is the key motif in all solution structures. The equilibrium between the Eu(III)–HEDP species is influenced by several parameters, i.e., pH, M:L, total Eu(III) and HEDP concentrations, and time. Overall, the present work sheds light on the very complex speciation in the HEDP–Eu(III) system and indicates that, for risk assessment of potential decorporation scenarios, side reactions of HEDP with trivalent actinides and lanthanides should also be taken into account.

The optimal approach for magnetic resonance imaging-guided online adaptive radiotherapy is currently unknown and needs to consider patient on-couch time constraints. The aim of this study was to compare two different plan optimization approaches. The comparison was performed in 238 clinically applied online-adapted treatment plans from 55 patients, in which the approach of re-optimization was selected based on the physician’s choice. For 33 patients where both optimization approaches were used at least once, the median treatment planning dose metrics of both target and organ at risk differed less than 1%. Therefore, we concluded that beam segment weight optimization was chosen adequately for most patients without compromising plan quality.

Visual sociologist Jerome Krase looks at how cities change with immigration, globalization, and gentrification, with a focus on Brooklyn as well as comparative work in cities around the world. He focuses on what can be learned through direct observation of the vernacular landscapes of neighborhoods where the interface between the public and private domains is individually and communally appropriated. He has argued consistently that ordinary residents have the power to change the meaning of a place by changing how it looks. His sociological practice has involved photography for decades, and he has developed a large visual archive of urban neighborhoods around the world. This illustrated interview focuses on the articulation of domestic, commercial, and real-estate practices, especially in Brooklyn, New York, and on the displacements, exchanges, and adaptations that characterize both vernacular agency and the academic use of the concept of “vernacular” across the social sciences.

The introduction of real-time imaging by magnetic resonance guided linear accelerators (MR-Linacs) enabled adaptive treatments and gating on the tumor position. Different end-to-end tests monitored the accuracy of our MR-Linac during the first year of clinical operation. We report on the stability of these tests covering a static, adaptive and gating workflow. Film measurements showed gamma passing rates of 96.4% ± 3.4% for the static tests (five measurements) and for the two adaptive tests 98.9% and 99.99%, respectively (criterion 2%/2mm). The gated point dose measurements in the breathing phantom were 2.7% lower than in the static phantom.

Abstract Background Online adaptive radiotherapy is intended to prevent plan degradation caused by inter-fractional tumor volume and shape changes, but time limitations make online re-planning challenging. The aim of this study was to compare the quality of online-adapted plans to their respective reference treatment plans. Methods Fifty-two patients treated on a ViewRay MRIdian Linac were included in this retrospective study. In total 238 online-adapted plans were analyzed, which were optimized with either changing of the segment weights (n = 85) or full re-optimization (n = 153). Five different treatment sites were evaluated: prostate, abdomen, liver, lung and pelvis. Dosimetric parameters of gross tumor volume (GTV), planning target volume (PTV), 2 cm ring around the PTV and organs at risk (OARs) were considered. The Wilcoxon signed-rank test was used to assess differences between online-adapted and reference treatment plans, p

Although 2-phosphonobutane-1,2,4,-tricarboxylic acid, PBTC, has manifold industrial applications, relevant and reliable data on the protonation of PBTC are poor. However, these data are critical parameters for ascertaining PBTC speciation, especially with regard to a sound structural and thermodynamic characterization of its metal ion complexes. A rigorous evaluation of pH-dependent 1H, 13C, and 31P chemical shifts along with accessible scalar spin–spin coupling constants (J) was performed in order to determine the pKa values of PBTC in 0.5 molal NaCl aqueous solution by means of nuclear magnetic resonance (NMR) spectroscopy. The phosphonate group revealed pKa values of 0.90 ± 0.02 and 9.79 ± 0.02, and the pKa values associated with the carboxylic groups are 3.92 ± 0.02, 4.76 ± 0.03, and 6.13 ± 0.03. Supported by DFT-calculated structures revealing strong intramolecular hydrogen bonding, the sequence of deprotonation could be unambiguously determined.

While the rise of television is a major cultural fact, the demographic, economic, social and cultural dynamics of post-war France, which extends well beyond the mid-1970s in the school fiels, leads to the implementation of policies that profoundly transform the place of vocational education within the education system. How did the televisual discourse account for it during this pivotal period of the 1970s-1980s, which is undergoing a profound change in the dominant economic and social paradigm? The study of audiovisual archives kept by the National Audiovisual Institute (INA) shows how the question of vocational education is integrated into a wider discourse, between denouncing the supposed gravities of the education system and exaltation of the modernizing work in progress, even as the media field is profoundly upset by the liberalization of the audiovisual sector.

Background and purpose: Photon radiotherapy has been established for the treatment of ocular melanoma (OM). Here we investigate the planning qualities of two different planning approaches, a combination of dynamic conformal arcs (DCA) complemented with multiple non-coplanar static intensity-modulated (IMRT) fields (DCA-IMRT), and volumetric modulated arc therapy (VMAT) in combination with automated planning (AP). Materials and methods: Thirteen consecutive patients treated for ocular melanoma with curative intent on a Linac-based radiosurgery system were analyzed. Fractionated stereotactic radiosurgery (fSRS) was applied using 50 Gy in 5 fractions using the combination of DCA-IMRT. Plans were reviewed and the thirteen cases were compared to plans obtained with optimized automated VMAT based on a set of 28 distinct patients treated with DCA-IMRT who were selected to generate the AP model for the prediction of dose volume constraints. Results: Overall, plan quality of DCA-IMRT was superior to AP with VMAT. PTV coverage did not exceed 107% in any case treated with DCA-IMRT, compared to seven patients with VMAT. The median PTV covered by >95% was 98.3% (91.9%–99.7%) with DCA-IMRT, compared to 95.1% (91.5%–97.9%) (p

We describe repeated episodes of hepatitis C (HCV) activation associated with initiation of highly active antiretroviral therapy (HAART) in two HIV/HCV coinfected individuals with undetectable serum HCV RNA. Both patients developed high HCV viremia (>1 million IU/mL) and elevations in aminotransferases >10 times upper limit of normal) within 4 months of starting HAART. This is the first report of clinically significant HCV activation in HCV-seropositive patients with initially undetectable HCV viremia. These observations suggest that flares of hepatitis C in the setting of the immune reconstitution inflammatory syndrome can occur even in those patients who have undetectable serum HCV levels prior to HAART initiation. [ABSTRACT FROM AUTHOR]

IntroductionThe subventricular zone (SVZ) in the brain is associated with gliomagenesis and resistance to treatment in glioblastoma. In this study, we investigate the prognostic role and biological characteristics of subventricular zone (SVZ) involvement in glioblastoma.MethodsWe analyzed T1-weighted, gadolinium-enhanced MR images of a retrospective cohort of 647 primary glioblastoma patients diagnosed between 2005-2013, and performed a multivariable Cox regression analysis to adjust the prognostic effect of SVZ involvement for clinical patient- and tumor-related factors. Protein expression patterns of a.o. markers of neural stem cellness (CD133 and GFAP-δ) and (epithelial-) mesenchymal transition (NF-κB, C/EBP-β and STAT3) were determined with immunohistochemistry on tissue microarrays containing 220 of the tumors. Molecular classification and mRNA expression-based gene set enrichment analyses, miRNA expression and SNP copy number analyses were performed on fresh frozen tissue obtained from 76 tumors. Confirmatory analyses were performed on glioblastoma TCGA/TCIA data.ResultsInvolvement of the SVZ was a significant adverse prognostic factor in glioblastoma, independent of age, KPS, surgery type and postoperative treatment. Tumor volume and postoperative complications did not explain this prognostic effect. SVZ contact was associated with increased nuclear expression of the (epithelial-) mesenchymal transition markers C/EBP-β and phospho-STAT3. SVZ contact was not associated with molecular subtype, distinct gene expression patterns, or markers of stem cellness. Our main findings were confirmed in a cohort of 229 TCGA/TCIA glioblastomas.ConclusionIn conclusion, involvement of the SVZ is an independent prognostic factor in glioblastoma, and associates with increased expression of key markers of (epithelial-) mesenchymal transformation, but does not correlate with stem cellness, molecular subtype, or specific (mi)RNA expression patterns.

Purpose: Stereotactic radiosurgery (SRS) is the preferred primary treatment option for patients with a limited number of asymptomatic brain metastases. In case of relapse after initial SRS the optimal salvage treatment is not well defined. Within this retrospective analysis, we investigated the feasibility of repeated courses of SRS to defer Whole-Brain Radiation Therapy (WBRT) and aimed to derive prognostic factors for patient selection.Materials and Methods: From 2014 until 2017, 42 patients with 197 brain metastases have been treated with multiple courses of SRS at our institution. Treatment was delivered as single fraction (18 or 20 Gy) or hypo-fractionated (6 fractions with 5 Gy) radiosurgery. Regular follow-up included clinical examination and contrast-enhanced cMRI at 3–4 months' intervals. Besides clinical and treatment related factors, brain metastasis velocity (BMV) as a newly described clinical prognostic metric was included and calculated between first and second treatment.Results: A median number of 1 lesion (range: 1–13) per course and a median of 2 courses (range: 2–6) per patient were administered resulting in a median of 4 (range: 2–14) metastases treated over time per patient. The median interval between SRS courses was 5.8 months (range: 0.9–35 months). With a median follow-up of 17.4 months (range: 4.6–45.5 months) after the first course of treatment, a local control rate of 84% was observed after 1 year and 67% after 2 years. Median time to out-of-field-brain-failure (OOFBF) was 7 months (95%CI 4–8 months). WBRT as a salvage treatment was eventually required in 7 patients (16.6%). Median overall survival (OS) has not been reached. Grouped by ds-GPA (≤ 2 vs. >2) the survival curves showed a significant split (p = 0.039). OS differed also significantly between BMV-risk groups when grouped into low vs. intermediate/high risk groups (p = 0.025). No grade 4 or 5 acute or late toxicity was observed.Conclusion: In selected patients with relapse after SRS for brain metastases, repeat courses of SRS were safe and minimized the need for rescue WBRT. The innovative, yet easy to calculate metric BMV may facilitate treatment decisions as a prognostic factor for OS.

O estudo dos usos da repetência no ensino primário francês no século 19 revela até que ponto esta era utilizada para facilitar a aprendizagem dos melhores alunos. Permitindo distinguir a elite escolar destinada ao êxito nos exames que certificavam os estudos primários, a seleção em cada etapa do percurso leva a relegar as crianças com dificuldades às series iniciais, onde é maior o número de alunos inscritos, junto aos jovens ingressantes. Esta situação não ocorre sem efeitos sobre as desigualdades educacionais, mesmo se estas são atenuadas pelo esforço de modernização empreendido pelos republicanos a partir dos anos 1880. Persistem, contudo, sob diferentes formas na história do sistema escolar francês.Palavras-chave: repetência escolar, França, desigualdade.MERITOCRACY AND THE USES OF SCHOOL FAILURE IN FRENCH PUBLIC ELEMENTARY SCHOOL FROM 1850 TO THE EARLY TWENTIETH CENTURYAbstractThe study of the uses of the school failure in French primary education in the nineteenth century reveals the extent to which this was used to facilitate the learning of the best students. It differentiates school elite destined for success in exams certifying that the primary studies, the selection at each stage of the journey leads to relegate children with difficulties to the initial series, where a greater number of students enrolled among the youth entrants. This situation is not without effects on educational inequalities, even if they are attenuated by the modernization efforts undertaken by Republicans from the 1880s. It remains, however, in different forms in the history of the French school system.Key-words: school failure,France, inequality.MERITOCRACIA Y LA UTILIZACIÓN DE LA REPETICIÓN EN LA ESCUELA PRIMARIA PÚBLICA FRANCESA DE 1850 A COMIENZOS DEL SIGLO 20ResumenEl estudio de los usos de la repetición en la escuela primaria francesa en el siglo 19 muestra el grado en que ésta es utilizada para facilitar el aprendizaje de los mejores estudiantes. Permitiendo diferenciar la élite escolar destinada al éxito en los exámenes que certifican los estudios primarios, la selección en cada una de las etapas del curso lleva a relegar a los niños con dificultades en la primera serie, donde hay el mayor número de estudiantes matriculados, junto con los jóvenes estudiantes. Esta situación no se produce sin efectos sobre las desigualdades educativas, incluso si estas se ven atenuadas por los esfuerzos de modernización emprendidos por los republicanos a partir del año 1880. Sin embargo, siguen existiendo en diversas formas en la historia del sistema escolar francés.Palabras-clave: tasas de fracaso escolar, Francia, desigualdad.MERITOCRATIE ET USAGES DU REDOUBLEMENT DANS L’ECOLE PRIMAIRE PUBLIQUE FRANÇAISE DES ANNEES 1850 AU DEBUT DU 20E SIECLERésuméL’étude de l’usage du redoublement dans l’enseignement primaire français au 19e siècle révèle à quel point il est alors employé pour faciliter les apprentissages des meilleurs élèves. En permettant de distinguer l’élite scolaire destinée à réussir les examens du certificat d’études primaires, la sélection à chaque étape du cursus conduit à la relégation des enfants en difficulté dans des petites classes aux effectifs plus chargés et regroupés avec de très jeunes débutants. Cette situation n’est pas sans avoir d’effets sur les inégalités scolaires, même si celles-ci sont atténuées par l’effort de modernisation entrepris par les républicains à partir des années 1880. Ils perdurent néanmoins sous différentes formes dans l’histoire du système scolaire français.Mots-clé: redoublement, France, inégalité.