bluuebunny/crossref_metadata_2025 huggingface dataset:
Uniqueness and stability for the solution of a nonlinear least squares problem
Authors: Huang Meng , Xu Zhiqiang
Published: October 2023

In this paper, we focus on the nonlinear least squares problem:

min

x

∈

H

d

‖
|
A

x

|
−

b

‖

\min _{{\boldsymbol {x}}\in \mathbb {H}^d}\|\lvert A{\boldsymbol {x}}\rvert -{\boldsymbol {b}}\|

where

A
∈

H

m
×
d

A\in \mathbb {H}^{m\times d}

,

b

∈

R

m

{\boldsymbol {b}}\in \mathbb {R}^m

with

H

∈

{

R

,

C

}

\mathbb {H}\in \left \{\mathbb {R},\mathbb {C}\right \}

and consider the uniqueness and stability of solutions. This problem arises in applications such as phase retrieval and absolute value rectification neural networks. While several results have been developed to characterize the uniqueness and stability of solutions when

b

=
|
A

x

0

|

{\boldsymbol {b}}=\lvert A{\boldsymbol {x}}_0\rvert

for some

x

0

∈

H

d

{\boldsymbol {x}}_0\in \mathbb {H}^d

, no existing results address the case where

b

{\boldsymbol {b}}

is arbitrary. In this paper, we investigate the uniqueness and stability of solutions for the more general case where

b

{\boldsymbol {b}}

is not necessarily equal to

|
A

x

0

|

\lvert A{\boldsymbol {x}}_0\rvert

for any

x

0

∈

H

d

{\boldsymbol {x}}_0\in \mathbb {H}^d

. We prove that for any matrix

A
∈

H

m
×
d

A\in \mathbb {H}^{m\times d}

, there is always a vector

b

∈

R

m

{\boldsymbol {b}}\in \mathbb {R}^m

for which the solution to the nonlinear least squares problem is not unique. However, we show that such “bad” vectors

b

{\boldsymbol {b}}

are negligible in practice; specifically, if

b

∈

R

m

{\boldsymbol {b}}\in \mathbb {R}_{ }^m

does not lie in some measure zero set, then the solution is unique. Furthermore, we establish certain conditions under which the solution is guaranteed to be unique. Regarding the stability of solutions, we prove that the solution is not uniformly stable. However, if we restrict the vectors

b

{\boldsymbol {b}}

to a convex set where the solution to the least squares problem is unique, then the solution becomes stable. To the best of our knowledge, our results represent the first theoretical results of the uniqueness and stability of solutions for the nonlinear least squares problem.
A note on the convex body isoperimetric conjecture in the plane
Authors: Wang Bo-Hshiung , Wang Ye-Kai
Published: October 2023

The convex body isoperimetric conjecture in the plane asserts that the least perimeter to enclose given area inside a unit disk is greater than inside any other convex set of area

π
\pi

. In this note we confirm two cases of the conjecture: perturbations of the unit disk and domains bounded by curves symmetric to both coordinate axes and having exactly four vertices.
Contractibility of the orbit space of the 𝑝-subgroup complex via Brown-Forman discrete Morse theory
Authors: Steinberg Benjamin
Published: October 2023

We give a simple proof that the orbit space of the

p
p

-subgroup complex of a finite group is contractible using Brown-Forman discrete Morse theory. This result was originally conjectured by Webb [Proc. Sympos. Pure Math., vol. 47, Amer. Math. Soc., Providence, RI, 1987, pp. 349–365] and proved by Symonds [Comment. Math. Helv. 73 (1998), pp. 400–405].
Exercise in hypoxia: a model from laboratory to on-field studies
Authors: Vignati Carlo , Contini Mauro , Salvioni Elisabetta , Lombardi Carolina , Caravita Sergio , Bilo Grzegorz , Swenson Erik R , Parati Gianfranco , Agostoni Piergiuseppe
Published: October 2023

Clinical outcome and quality of life of patients with chronic heart failure (HF) have greatly improved over the last two decades. These results and the availability of modern lifts allow many cardiac patients to spend leisure time at altitude. Heart failure per se does not impede a safe stay at altitude, but exercise at both simulated and real altitudes is associated with a reduction in performance, which is inversely proportional to HF severity. For example, in normal subjects, the reduction in functional capacity is ∼2% every 1000 m altitude increase, whereas it is 4 and 10% in HF patients with normal or slightly diminished exercise capacity and in HF patients with markedly diminished exercise capacity, respectively. Also, the on-field experience with HF patients at altitude confirms safety and shows overall similar data to that reported at simulated altitude. Even ‘optimal’ HF treatment in patients spending time at altitude or at hypoxic conditions is likely different from optimal treatment at sea level, particularly with regard to the selectivity of β-blockers. Furthermore, high altitude, both simulated and on-field, represents a stimulating model of hypoxia in HF patients and healthy subjects. Our data suggest that spending time at altitude (<3500 m) can be safe even for HF patients, provided that subjects are free from comorbidities that may directly interfere with the adaptation to altitude and are stable. However, HF patients experience a reduction of exercise capacity directly proportional to HF severity and altitude. Finally, HF patients should be tested for functional capacity and must undergo a specific ‘hypoxic-tailored treatment’ to avoid pharmacological interference with altitude adaptation mechanisms, particularly with regard to the selectivity of β-blockers.
Effects of detraining on left ventricular mass in endurance-trained individuals: a systematic review and meta-analysis
Authors: Massarotto Raffaele J , Campbell Allison J , Kreiter Elizabeth , Claydon Victoria E , Cote Anita T
Published: October 2023

Aims

Detraining refers to a loss of training adaptations resulting from reductions in training stimulus due to illness, injury, or active recovery breaks in a training cycle and is associated with a reduction in left ventricular mass (LVM). The purpose of this study was to conduct a systematic review and meta-analysis to determine the influence of detraining on LVM in endurance-trained, healthy individuals.

Methods and results

Using electronic databases (e.g. EMBASE and MEDLINE), a literature search was performed looking for prospective detraining studies in humans. Inclusion criteria were adults, endurance-trained individuals with no known chronic disease, detraining intervention >1 week, and pre- and post-detraining LVM reported. A pooled statistic for random effects was used to assess changes in LVM with detraining. Fifteen investigations (19 analyses) with a total of 196 participants (ages 18–55 years, 15% female) met inclusion criteria, with detraining ranging between 1.4 and 15 weeks. The meta-analysis revealed a significant reduction in LVM with detraining (standardized mean difference = −0.586; 95% confidence interval = −0.817, −0.355; P < 0.001). Independently, length of detraining was not correlated with the change in LVM. However, a meta-regression model revealed length of the detraining, when training status was accounted for, was associated with the reduction of LVM (Q = 15.20, df = 3, P = 0.0017). Highly trained/elite athletes had greater reductions in LVM compared with recreational and newly trained individuals (P < 0.01). Limitations included relatively few female participants and inconsistent reporting of intervention details.

Conclusion

In summary, LVM is reduced following detraining of one week or more. Further research may provide a greater understanding of the effects of sex, age, and type of detraining on changes in LVM in endurance-trained individuals.
Oxidative profile, inflammatory responses and δ-aminolevulinate dehydratase enzyme activity in influenza B virus infection
Authors: Bulegon Jovana Simonetti , Weber Andressa de Azambuja Pias , de Souza Manoela Dias , Viero Fernanda Tibolla , Pillat Micheli Mainardi , Gonçalves Thissiane de Lima
Published: October 2023

The aim of the current study was to determine the activity of the delta-aminolevulinate dehydratase (δ-ALA-D) enzyme, oxidative stress biomarkers and the expression of cytokines in those infected with influenza B virus (IBV). To evaluate the activity of the δ-ALA-D enzyme, lipid peroxidation was estimated as levels of thiobarbituric acid reactive substances, protein and non-protein thiol groups, ferric-reducing antioxidant power (FRAP), vitamin C concentration and cytokine levels in IBV-infected individuals (n  = 50) and a control group (n = 30). δ-ALA-D activity was significantly lower in IBV-infected individuals compared with controls, as well as levels of thiols, vitamin C and FRAP. Lipid peroxidation and cytokine levels of IL-6, IL-10, IL-17A and IFN-y were statistically higher in the IBV group. In conclusion, we found evidence of the generation of oxidants, the depletion of the antioxidant system, decrease in the activity of the δ-ALA-D enzyme and an increase in the synthesis of cytokines, thus contributing to a better understanding of oxidative and inflammatory pathways during IBV infection.
Dada in the Underground: linkeck and West Berlin’s Anti-Authoritarian Newspapers, 1968–69
Authors: Davies Mererid Puw
Published: October 2023

This article explores the importance of periodicals for the 1960s protest movements in West Germany. It opens with the significance of both mainstream news media and New Left journals. Attention then turns to a different class of periodical, the anti-authoritarian underground newspaper, examined here through one emblematic example, linkeck [leftangle], which was produced in a centre of revolt, West Berlin, in 1968–69. While linkeck had limited circulation and was short-lived, it achieved notoriety and gave rise to a series of successors. To understand linkeck’s impact and meanings, this article comments on its origins in an anti-authoritarian commune and its philosophy on work, politics and relationships; its ephemerality; its influences and interests; its distinctive style and its conflicts with the law. In conclusion, the essay argues that linkeck epitomizes anti-authoritarian themes and form, and that periodicals were the movements’ most characteristic genre. Throughout, the essay also considers key resonances between linkeck and earlier twentieth-century (anti-)artistic avant-gardes, notably Dada.
Dietary supplementation with garcinol during late gestation alleviates disorders of bile acid metabolism and improves the performance of sows and newborn piglets
Authors: Wang Tongxin , Huang Lu , Xia Changhong , Zhou Yan , Yao Weilei , Zhang Liwen , Huang Feiruo
Published: October 2023

The present study was conducted to evaluate the effects of dietary garcinol supplementation during late gestation on bile acid metabolism and performance of sows. Sixty sows (Duroc × Yorkshire × Landrace; second- or third-parity; n = 20) with disorder of bile acid metabolism were randomly divided into three groups: control diet (CON; basal diet), basal diet with 200 mg garcinol (Low Gar), and basal diet with 600 mg garcinol (High Gar) per kg of feed. The body weight (BW); backfat thickness and litter size of the sows; and birth weight, weaning weight, and mortality of piglets were recorded. Sows’ blood was collected for the measurements of hematological parameters and antioxidative and immune indexes, and indicators related to bile acid metabolism, respectively. The colostrum and fecal samples of the sows were also collected for analysis of colostrum composition and apparent total tract nutrient digestibility. Garcinol had no effect on the BW and backfat thickness of the sows but significantly decreased the mortality and number of weak litter (P < 0.05). Moreover, the white blood cell counts, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activity in the plasma of the sows were increased more significantly (P < 0.05) in the garcinol groups than that in the CON group, whereas the malondialdehyde (MDA) content was decreased (P < 0.05). Dietary supplementation with garcinol significantly reduced TBA concentrations (P < 0.05). The content of immunoglobulin A (IgA) and immunoglobulin G (IgG) in the plasma and in colostrum of sows were increased more significantly (P < 0.05) in the garcinol groups than that in the CON group. In addition, dry matter (DM), Ash, and EE in the colostrum were similar between groups (P > 0.05), whereas the garcinol significantly increased the crude protein (CP) in the colostrum. The apparent total tract nutrient digestibility was similar between treatments. Garcinol treatment induced a gradually decreased (P > 0.05) the expression of genes involved in BA synthesis (CYP7A1, CYP8B1), BA uptake (NTCP, OATP1A2), BA secretion (BSEP and MRP2), BA detoxification (SULT2A1), and BA efflux into the blood circulation (OSTβ). Collectively, this study indicates that sows fed with garcinol in late gestation showed relieved bile acid metabolism disorder and improved sows performance, antioxidative status, colostrum protein content, showing promise in natural plant extract nutrition for sows with disorder of bile acid metabolism.
Metaphorical Uses of Proper Names and the Continuity Hypothesis
Authors: Hesse Jacob , Genovesi Chris , Corazza Eros
Published: October 2023

According to proponents of the continuity hypothesis, metaphors represent one end of a spectrum of linguistic phenomena, which includes various forms of loosening/broadening, such as category extensions and approximations, as well as hyperbolic interpretations. The continuity hypothesis is used to establish that the inferences derived from the set of linguistic expressions mentioned above result from the same or nearly similar pragmatic processes. In this paper, we want to challenge that particular aspect of the continuity hypothesis. We do so based on considerations and analysis of an understudied linguistic phenomenon that we call the metaphorical uses of proper names (MPNs). We first explain how MPNs represent a unique linguistic class distinguishable from, for example, nicknames. In addition, we offer some remarks on how MPNs can be understood against the background of current debates between referentialists and predicativists about names. Our discussion leads us to conclude that MPNs are categorically different from literal interpretations of proper names. We spell out the consequences that the results of our analysis have for the continuity hypothesis.
Treatment of recurrent hernia in peritoneal dialysis patients
Authors: Hao Long , Hong Xiaoming , Sha Hongcun , Zhao Yu
Published: October 2023

Peritoneal dialysis (PD) is the most commonly used treatment for patients with end-stage renal disease and has the advantages of simple operation and low treatment costs. However, long-term PD may lead to inguinal hernia formation, which needs to be repaired as early as possible. There are many studies on this kind of hernia, but there are few reports about how to treat recurrent hernia in PD patients. Therefore, we present a case of a female PD patient who suffered from a recurrent femoral hernia after primary hernioplasty. We successfully proceeded with treatment by laparoscopic transabdominal preperitoneal hernia repair. The patient was scheduled to receive temporary haemodialysis until the normal PD dose was restored. After 36 months of follow-up, we found that there was no recurrence of hernia, and the function of the PD catheter was normal.
Corpus philology: Using the Dictionary of Old English to get bigger data for Old English spelling variation
Authors: Faulkner Mark
Published: October 2023

This article presents a methodology for obtaining large datasets for the spelling of individual phonological segments in Old English texts, based on searching the Dictionary of Old English Corpus for the attested spellings listed in the Dictionary of Old English A-H. It exemplifies this ‘corpus philology’ through a study of 216,526 spellings for words beginning with h followed by a vowel, using a variety of techniques to evaluate the methodology’s precision and recall, which are calculated as very high for initial spellings (precision 100% precision, recall 92.1%) and moderate, but still usable, for less spellings (precision 85.5%, recall 58.3%). Data for fourteen other segments related to the behaviour of h- in Old English is presented in the Supplementary Materials that complement the paper online. This dataset of 379,484 spellings from 2,605 Old English texts is shown to seriously problematize the findings of traditional philology, the conclusions of which are in contrast based on only a handful of spellings from a few texts, and to have the potential to radically enhance our understanding of the literary and linguistic histories of English.
Transmission problems? An embedded approach for unification of Latin prefixes and text variants during text matching
Authors: Schropp Franziska , Konrad Thomas E , Revellio Marie , Feichtinger Barbara
Published: October 2023

The manuscript tradition of pre-modern texts poses a specific problem for scholars in the field of Digital Humanities: before printing made the production of standardized editions of texts feasible, copying texts by hand (and often by different people) was inherently an error-prone process, which not only led to differences in wording but also in spelling—across multiple transmitted variants. This applies especially to ancient texts, where the temporal distances to the archetypes tend to be fairly large. In computerized research, especially in the case of text matching within the field of citation research and text mining, these differences in wording and spelling—however small they might be—may prevent a successful matching of texts. This case study presents a solution for the problem of textual differences arising from (non-)assimilated prefixes in Latin, a feature where modern editions mostly differ from author to author, but sometimes even between two editions of the same text. With regard to the letters of the church father Jerome as well as Virgil’s Eclogues, Georgics, and Aeneid, two approaches are compared in terms of error rate and efficiency for a given set of prefixes: (1) performing and (2) reversing corpus-wide assimilation. Moreover, the broader implications of the (in-)accessibility of text-critical data in digital editions are discussed. Finally, general desiderata regarding text-critical data for computerized research on classical texts are elaborated.
Detection of the significant impact of source clustering on higher order statistics with DES Year 3 weak gravitational lensing data
Authors: Gatti M , Jeffrey N , Whiteway L , Ajani V , Kacprzak T , Zürcher D , Chang C , Jain B , Blazek J , Krause E , Alarcon A , Amon A , Bechtol K , Becker M , Bernstein G , Campos A , Chen R , Choi A , Davis C , Derose J , Diehl H T , Dodelson S , Doux C , Eckert K , Elvin-Poole J , Everett S , Ferte A , Gruen D , Gruendl R , Harrison I , Hartley W G , Herner K , Huff E M , Jarvis M , Kuropatkin N , Leget P F , MacCrann N , McCullough J , Myles J , Navarro-Alsina A , Pandey S , Prat J , Raveri M , Rollins R P , Roodman A , Sanchez C , Secco L F , Sevilla-Noarbe I , Sheldon E , Shin T , Troxel M , Tutusaus I , Varga T N , Yanny B , Yin B , Zhang Y , Zuntz J , Allam S S , Alves O , Aguena M , Bacon D , Bertin E , Brooks D , Burke D L , Rosell A Carnero , Carretero J , Cawthon R , da Costa L N , Davis T M , De Vicente J , Desai S , Doel P , García-Bellido J , Giannini G , Gutierrez G , Ferrero I , Frieman J , Hinton S R , Hollowood D L , Honscheid K , James D J , Kuehn K , Lahav O , Marshall J L , Mena-Fernández J , Miquel R , Ogando R L C , Palmese A , Pereira M E S , Malagón A A Plazas , Rodriguez-Monroy M , Samuroff S , Sanchez E , Schubnell M , Smith M , Sobreira F , Suchyta E , Swanson M E C , Tarle G , Weaverdyck N , Wiseman P ,   DES Collaboration
Published: October 2023

We measure the impact of source galaxy clustering on higher order summary statistics of weak gravitational lensing data. By comparing simulated data with galaxies that either trace or do not trace the underlying density field, we show that this effect can exceed measurement uncertainties for common higher order statistics for certain analysis choices. We evaluate the impact on different weak lensing observables, finding that third moments and wavelet phase harmonics are more affected than peak count statistics. Using Dark Energy Survey (DES) Year 3 (Y3) data, we construct null tests for the source-clustering-free case, finding a p-value of p = 4 × 10−3 (2.6σ) using third-order map moments and p = 3 × 10−11 (6.5σ) using wavelet phase harmonics. The impact of source clustering on cosmological inference can be either included in the model or minimized through ad hoc procedures (e.g. scale cuts). We verify that the procedures adopted in existing DES Y3 cosmological analyses were sufficient to render this effect negligible. Failing to account for source clustering can significantly impact cosmological inference from higher order gravitational lensing statistics, e.g. higher order N-point functions, wavelet-moment observables, and deep learning or field-level summary statistics of weak lensing maps.
Immune signatures of checkpoint inhibitor-induced autoimmunity—A focus on neurotoxicity
Authors: Müller-Jensen Leonie , Schulz Axel R , Mei Henrik E , Mohr Raphael , Ulrich Claas , Knape Philipp , Frost Nikolaj , Frischbutter Stefan , Kunkel Desiree , Schinke Christian , Ginesta Roque Lorena , Maierhof Smilla K , Nickel Florian T , Heinzerling Lucie , Endres Matthias , Boehmerle Wolfgang , Huehnchen Petra , Knauss Samuel
Published: October 2023

Background

Neurologic immune-related adverse events (irAE-n) are rare but severe toxicities of immune checkpoint inhibitor (ICI) treatment. To overcome diagnostic and therapeutic challenges, a better mechanistic understanding of irAE-n is paramount.

Methods

In this observational cohort study, we collected serum and peripheral blood samples from 34 consecutive cancer patients with irAE-n (during acute illness) and 49 cancer control patients without irAE-n (pre- and on-ICI treatment, n = 44 without high-grade irAEs, n = 5 with high-grade nonneurologic irAEs). Patients received either anti-programmed cell death protein (PD)-1 or anti-PD ligand-1 monotherapy or anti-PD-1/anti-cytotoxic T-lymphocyte-associated protein-4 combination therapy. Most common cancers were melanoma, lung cancer, and hepatocellular carcinoma. Peripheral blood immune profiling was performed using 48-marker single-cell mass cytometry and a multiplex cytokine assay.

Results

During acute illness, patients with irAE-n presented higher frequencies of cluster of differentiation (CD)8+ effector memory type (EM-)1 and central memory (CM) T cells compared to controls without irAEs. Multiorgan immunotoxicities (neurologic + nonneurologic) were associated with higher CD8+ EM1 T cell counts. While there were no B cell changes in the overall cohort, we detected a marked decrease of IgD− CD11c+ CD21low and IgD− CD24+ CD21high B cells in a subgroup of patients with autoantibody-positive irAE-n. We further identified signatures indicative of enhanced chemotaxis and inflammation in irAE-n patients and discovered C-X-C motif chemokine ligand (CXCL)10 as a promising marker to diagnose high-grade immunotoxicities such as irAE-n.

Conclusions

We demonstrate profound and partly subgroup-specific immune cell dysregulation in irAE-n patients, which may guide future biomarker development and targeted treatment approaches.
ChatGPT in research and health professions education: challenges, opportunities, and future directions
Authors: Sahu Pradeep Kumar , Benjamin Lisa A , Singh Aswal Gunjan , Williams-Persad Arlene
Published: October 2023

ChatGPT was launched by OpenAI in November 2022 and within 2 months it became popular across a wide range of industrial, social, and intellectual contexts including healthcare education. This article reviews the impact of ChatGPT on research and health professions education by identifying the challenges and opportunities in these fields. Additionally, it aims to provide future directions to mitigate the challenges and maximize the benefits of this technology in health professions education. ChatGPT has the potential to revolutionize the field of research and health professions education. However, there is a need to address ethical concerns and limitations such as lack of real-time data, data inaccuracies, biases, plagiarism, and copyright infringement before its implementation. Future research can highlight the ways to mitigate these challenges; establish guidelines and policies; and explore how effectively ChatGPT and other AI tools can be used in the field of research and healthcare professions education.
EURADOS ISO/IEC 17025 guidance for IMS: suggestions on how to interpret and implement the requirements including examples from accredited laboratories
Authors: Petrovic B , Martin R , Romero A M , Askounis P , Buchanan L , Rossi F , Bernat R , Alves J G
Published: October 2023

Individual monitoring of external radiation is an activity usually regulated by national regulatory bodies in most countries. Regulations generally contain technical requirements to be met by the individual monitoring services (IMS), in order to ensure that the measurements are correct and therefore the dosimetry results are reliable. In some countries, the requirements include or even consist of the accreditation of the service according to the standard ISO/IEC 17025: ‘General requirements for the competence of testing and calibration laboratories.’ It is a fact that accreditation is a growing trend among European IMS as a way to guarantee confidence in their technical competence. The acceptance of the dosimetry results between countries and their indentation in the respective National Dose Registries is facilitated if laboratories conform to the ISO/IEC 17025 standard. In the framework of the activities of EURADOS (European Radiation Dosimetry Group) working group 2 ‘Harmonization of Individual Monitoring in Europe’ and attending to the concern of many European IMS in the process of accreditation, a guide has been prepared. The purpose was to assist and encourage IMS to apply for accreditation and to share the authors’ own experience with the process. The guide intends to be a practical reference for IMS on how to interpret and implement the ISO/IEC 17025 requirements to the specific activity of a personal dosimetry service for external radiation, emphasizing those aspects of special interest. It includes examples from dosimetry laboratories already accredited. The major novelties from a new edition of ISO/IEC 17025: 2017 are also identified in the guide. Finally, the guide aims to assist the auditing process, giving examples of auditor’s questions and how to show evidence of compliance. The main findings are presented.
The European Radiation Dosimetry Group—a 40 year success story
Authors: Rühm Werner , Pihet Pascal , Schuhmacher Helmut
Published: October 2023

The European Radiation Dosimetry Group (EURADOS) was founded in 1982. Since then, the group has continuously developed and is currently a network of 80 institutions and more than 600 individual scientists across Europe, including exchange with the scientific community outside of Europe. EURADOS supports research and development of dosimetry and harmonising dosimetric practices. This paper describes the major milestones in the history of the organization. It starts from the very beginning when the idea was born and describes periods during which the role and strategy of the network had to be defined, elaborated and refined. Finally, it ends to date where EURADOS appears as an independent self-sustainable association, which is a reliable partner for various international organisations in radiation research and radiation protection. Major activities of EURADOS are highlighted such as (1) establishment and coordination of Working Groups, (2) regular organization of dosimetric intercomparisons for quality assurance of dosimetry procedures, (3) development and organization of education and training events, and (4) contributions towards the development of strategic and integrated radiation research in Europe.
Calibration of the W-PIE neutron spectrometer at CERF reference facility
Authors: Cirillo Andrea , Caresana Marco
Published: October 2023

The W-PIE is a cosmic neutron spectrometer used for environmental measurements, developed by Politecnico di Milano. The instrument is based on the Artkis M800 thermal neutron detector and works as a 4-channel spectrometer for detecting neutrons in the energy range of 0.01 eV–1 GeV. After the spectrometer had been calibrated in some monoenergetic neutron fields at the PIAF facility of PTB, the instrument was tested in the neutron field generated at the CERF facility, whose spectrum fairly resembles the cosmic one. This measurement is a precious tool for predicting the performance of the instrument in a realistic situation.
Development of A 14.8-MEV Mono-Energetic Neutron Field in Korea Research Institute of Standards and Science
Authors: Yoon Young Soo , Kim Jungho , Park Hyeoungwoo , Park Hyeonseo
Published: October 2023

A standard irradiation field for 14.8-MeV neutrons is under development for mono-energetic neutron standards research in the Korea Research Institute of Standards and Science, Republic of Korea. We developed a target chamber with the associated alpha particle (AAP) system for 14.8-MeV mono-energetic neutrons by a T(d,n)4He reaction. We designed the target chamber and the AAP detector system using a two-body kinematic calculation. We conducted simulations of the T(d,n)4He reaction on a tritiated target to determine a specification of the target and the AAP detector. This paper will discuss the simulation and calculation results for the associated particle system design.
Experiences in transitioning a testing laboratoryto the new ISO/IEC 17025:2017 standard
Authors: Hajek Michael , Bavio Marta A , Benesch Tobias N , Suárez Rodolfo Cruz , Hamel Nadia , Pinak Miroslav , Tucker David M , Wilding Allison
Published: October 2023

Since its inception, the international quality standard ISO/IEC 17025 has been revised twice. The most recent edition adopted a new structure to align with other conformity assessment and quality management standards, harmonized the terminology with the International Vocabulary of Metrology and introduced the concept of risk-based thinking. This paper disseminates the experience of the IAEA Radiation Safety Technical Services Laboratory in successful transition and re-accreditation to ISO/IEC 17025:2017. It covers all stages of the transition cycle: from conducting a gap analysis between the existing quality system and the requirements in the revised standard, updating the corresponding quality documents, developing training and communication plans for laboratory personnel, to monitoring the changes and improving the system through auditing, management review and participation in proficiency testing schemes. Lessons learned about building operational resilience and maintaining a business continuity management system to prepare for, respond to, and recover from disruptions are considered.
Assessment of the impact on a PADC neutron dosimetry system of the new operational dose quantities proposed in ICRU report 95
Authors: Moreno Brahim , Million Marc , Thomas David , Taylor Graeme
Published: October 2023

The International Commission on Radiation Units and Measurements, ICRU, have recommended, in ICRU Report 95, the adoption of new operational quantities for use in radiation protection monitoring. Their implementation will pose problems for instrument manufacturers supplying area dosemeters and for individual monitoring services providing personal dosemeters for radiation workers. The problems arise for photon, neutron and beta dosimetry, but this paper deals solely with neutron personal dosemeters based on poly-allyl diglycol carbonate (PADC) plastic. It presents information on the problems to be expected based on data from calibrations of actual personal neutron dosemeters in terms of the existing dose quantities.
Application of LiMgPO4 crystal for proton beam quality control in radiotherapy
Authors: Wróbel Damian , Kowalski Tomasz , Kusyk Sebastian , Marczewska Barbara , Nowak Tomasz , Olko Paweł , Swakoń Jan
Published: October 2023

The radioluminescence (RL) emitted by LiMgPO4 detector under proton beam irradiation was investigated in real time at the radiotherapy facility in the Institute of Nuclear Physics Polish Academy of Sciences in Krakow. The facility uses protons accelerated by the AIC-144 isochronous cyclotron up to the energy of 60 MeV. The measurements of RL were carried out using a remote optical fiber device with a luminophore detector and photomultiplier located at opposite ends of the optical fiber. A thin slice of LiMgPO4 doped with Tm (1.2 mol%) crystal was exposed to the proton beam. The tested detector allowed for the measurement of proton beam current, flux fluence and determination of proton beam time structure parameters. The investigation of LiMgPO4 crystal showed its high sensitivity, fast reaction time to irradiation and possibility of application as the detector for control of proton beam parameters.
Measurements in pulsed neutron fields
Authors: Caresana Marco , Cirillo Andrea , Bolzonella Matteo
Published: October 2023

Dosimetry in pulsed and mixed radiation fields represents an important challenge in radiation measurements, because in several accelerator technologies, the acceleration occurs in bunches of particles with short time duration, producing intense radiation pulses spaced by a relatively long time of beam off. The stray mixed radiation field generated around these installations maintains the same time structure as the primary beam and causes a problem in workplace fields’ monitoring. Active neutron detectors normally used in steady neutron fields, specifically REM-counters and Bonner sphere spectrometers, can suffer pulsed fields because of the high dead time losses during the bursts and are often inadequate for pulsed field monitoring. This work reviews the efforts of European Radiation Dosimetry Group (EURADOS), and in particular of the Working Group 11 ‘High Energy Radiation Fields’, to define the problem, characterize instrumentation and to propose solutions to the issue of pulsed and mixed radiation fields. Despite the EURADOS initiative, several open issues still remain. A metrological traceability for pulsed neutron fields is missing. There is still room for the optimization and better characterization of available instruments. Initiatives of education and training are required.
Personal dosimetry at the Paul Scherrer Institute
Authors: Mayer Sabine , Bossin Lily , Christensen Jeppe B , Pedrazzi Lisa , Yukihara Eduardo G
Published: October 2023

The Paul Scherrer Institute (PSI) is the largest research institute for natural and engineering sciences in Switzerland. PSI develops, builds and operates complex large research facilities. Every year, >2400 scientists from Switzerland and around the world come to PSI to use the facilities and to carry out experiments. Many areas at PSI are radiation protection areas. Depending on the radiation protection area, the work carried out and the time the users spend in these areas, they have to carry a personal dosemeter. PSI runs an individual monitoring service in compliance with the Swiss legislation on radiological protection and approved by the Swiss Federal Nuclear Safety Inspectorate. The service provides about 35 000 dosemeters per year for the internal and external customers consisting of whole-body dosemeters for photons and neutrons as well as extremity dosemeters. This paper gives an overview on the employed personal dosimetry techniques by the individual monitoring service of PSI, the number of distributed dosemeters for internal and external customers and statistics about the measured doses at PSI over 30 years.
Microdosimetry of a 62-MeV clinical proton beam with five detectors
Authors: Bianchi A , Agosteo S , Bortot D , Cirrone G A P , Colautti P , La Tessa C , Mazzucconi D , Missiaggia M , Petringa G , Rosenfeld A B , Selva A , Tran L , Verona C , Verona Rinati G , Conte V
Published: October 2023

In proton therapy, most treatment planning systems (TPS) use a fixed relative biological effectiveness (RBE) of 1.1 all along the depth-dose profile. Innovative TPS are now investigated considering the variability of RBE with radiation quality. New TPS need an experimental verification in the quality assurance (QA) routine in clinics, but RBE data are usually obtained with radiobiological measurements that are time consuming and not suitable for daily QA. Microdosimetry is a useful tool based on physical measurements which can monitor the radiation quality. Several microdosimeters are available in different research institutions, which could potentially be used for the QA in TPS. In this study, the response functions of five detectors in the same 62-MeV proton Spread Out Bragg Peak is compared in terms of spectral distributions and their average values and microdosimetric RBE. Their different response function has been commented and must be considered in the clinical practice.
Microdosimetric analysis of the radiation quality of two different proton beams in the distal edge of the depth-dose profile
Authors: Bianchi A , Selva A , Rossignoli M , Pasquato F , Missiaggia M , La Tessa C , Scifoni E , Tommasino F , Conte V
Published: October 2023

Proton-therapy exploits the advantageous depth-dose profile of protons to induce the highest damage to tumoral cells in the last millimetres of their range in sharp Bragg Peak. To cover the whole tumoral volume, beams of different energies are combined to create the Spread Out Bragg Peak (SOBP). In passive modulated beams, the energy spread is created with modulators in which the highest energy beam is degraded through different thicknesses of calibrated plastic materials. The highest energy is chosen depending on the deepest point that needs to be treated. This study aims to investigate differences in the radiation quality in the distal edge of SOBP beams with different initial energy and modulation techniques based on microdosimetric measurements with mini Tissue-Equivalent Proportional Counters. The beams investigated are the 62 MeV proton SOBP of the clinical facility of CATANA and the 148 MeV proton SOBP of the research beam line of the proton-therapy centre of Trento.
Source efficiency of alpha-emitters applied to the skin surface
Authors: Kim E , Narita M , Takashima Y , Nakata A , Tani K , Kurihara O
Published: October 2023

Skin surface contamination by alpha-emitters is in itself not hazardous, but it would cause significant internal exposure in the case of injured skin as well as misjudgment in direct in vivo measurements (e.g. lung counting). The present study determined the source efficiency of alpha-emitters (241Am) applied to swine skin samples by analysing the observed alpha-particle energy spectra using advanced alpha-spectrometric simulation. Based on our results, the source efficiency was determined to be 0.365 (alpha-particle s−1 per Bq) on average (c.f. 0.5 in the case of no self-absorption in the source). The decrease in source efficiency would be attributed primarily to the radionuclide entering hair follicles or deep wrinkles. The degradation of the measured spectra from the skin samples indicates the penetration of some radionuclides into the upper layers of the stratum corneum. Although this study was limited to results obtained from swine skin samples, it suggests that irregularities in the skin surface may affect direct alpha measurements.
Comparison of cell casted and 3D-printed plastic scintillators for dosimetry applications
Authors: Kulig D , Kapłon Ł , Moskal G , Beddar S , Fiutowski T , Górska W , Hajduga J , Jurgielewicz P , Kabat D , Kalecińska K , Kopeć M , Koperny S , Mindur B , Moroń J , Niedźwiecki S , Silarski M , Sobczuk F , Szumlak T , Ruciński A
Published: October 2023

Currently, the most used methods of plastic scintillator (PS) manufacturing are cell casting and bulk polymerisation, extrusion, injection molding, whereas digital light processing (DLP) 3D printing technique has been recently introduced. For our research, we measured blue-emitting EJ-200, EJ-208, green-emitting EJ-260, EJ-262 cell cast and two types of blue-emitting DLP-printed PSs. The light output of the samples, with the same dimension of 10 mm × 10 mm × 10 mm, was compared. The light output of the samples, relative to the reference EJ-200 cell-cast scintillator, equals about 40–49 and 70–73% for two types of 3D-printed, and two green-emitting cell-casted PSs, respectively. Performance of the investigated scintillators is sufficient to use them in a plastic scintillation dosemeter operating in high fluence gamma radiation fields.
First microdosimetric measurements with a tissue-equivalent proportional counter at the MedAustron ion-beam therapy facility
Authors: Barna Sandra , Meouchi Cynthia , Magrin Giulio , Bianchi Anna , Conte Valeria , Selva Anna , Stock Markus , Resch Andreas Franz , Georg Dietmar , Palmans Hugo
Published: October 2023

The aim of this work is to present the first microdosimetric spectra measured with a miniaturised tissue-equivalent proportional counter in the clinical environment of the MedAustron ion-beam therapy facility. These spectra were gathered with a 62.4-MeV proton beam and have been compared with microdosimetric spectra measured in the 62-MeV clinical proton beam of the CATANA beam line. Monte Carlo simulations were performed using the Geant4 toolkit GATE and a fully commissioned clinical beam line model. Finally, similarities and discrepancies of the measured data to simulations based on a simple and complex detector geometry are discussed.
Energy imparted and ionisation yield at the nanometre scale: results for extended beams
Authors: Selva Anna , Bolst David , Bianchi Anna , Guatelli Susanna , Conte Valeria
Published: October 2023

The metrological problem of interpreting ionisation-based micro- and nanodosimetric measurements in terms of quantities proportional to energy imparted becomes particularly relevant when the sensitive volume (SV) size is in the nanometre range. At these scales, a constant W-value cannot be assumed, and the stochastics of the energy transfer per single collision could play a more important role. This problem was recently analysed by our group by means of track-structure Monte Carlo simulations with the Geant4-DNA code, finding a strong correlation between the energy imparted and ionisation yield also for SV diameters of 1 nm. As the previous study was limited to primary beams of radius zero crossing the sensitive sphere along its diameter, it is the aim of the present work to extend the analysis to beams with a radius larger than the dimensions of the SV, to better assess the role played by secondary electrons.
Extended time-of-flight measurements down to 100 keV at the AMANDE facility with a stilbene scintillator
Authors: Petit Michael , Di Chicco Augusto , Sardet Alix , Babut Richard , Jacqmin Robert , Stout Brian
Published: October 2023

The time-of-flight (ToF) method with scintillators is routinely used for determining neutron energy. However, a technical difficulty related to the loss of scintillator efficiency below 1 MeV makes this technique difficult to implement for the energy decade [100 keV–1 MeV]. New crystal production techniques provide stilbene scintillators efficient in this low neutron energy region, making it possible to extend the ToF technique below 1 MeV. In this manner, measurements of secondary reactions (d,n) on carbon or oxygen nuclei in this range become feasible, which should lead to improved reference calibration conditions in neutron fields produced by a deuterium ion beam.
Effectiveness of simplified dose estimation equations for triage after criticality accident—a case study of dose assessment in the JCO criticality accident
Authors: Kowatari M , Kim E , Tani K , Naito M , Tamakuma Y , Kurihara O
Published: October 2023

The dosimetry for the triage of personnel encountering a criticality accident was investigated. The JCO criticality accident of 1999 was selected as a case study, and attention was paid to the identification and the segregation of severely exposed personnel. A series of Monte Carlo calculations revealed that simplified equations proposed by ANSI to estimate dose with respect to distance work well to determine the region of interest for triage.
Characterization of small radiophotoluminescence dosemeter in terms of H
P(0.07) for extremity dose monitoring of medical personnel
Authors: Kowatari M , Yoshitomi H , Nagamoto K , Nakagami K , Moritake T , Kunugita N
Published: October 2023

An additional extremity monitoring using a ring badge must be appropriately conducted for inhomogeneous exposure around radiation workers’ extremity. Commercially available glass dosemeters are characterized in terms of Hp(0.07) for the application of additional extremity monitoring. A series of experiments demonstrated that the response of the model GD-352M radiophotoluminescence dosemeter fully matched the IEC’s criteria for an extremity dosemeter for medical personnel. Although the model GD-302M has excellent angular dependence, the material and the shape of energy compensation filter still need to be optimized to improve its energy dependence in the range between 30 and 100 keV. The combine use of both types of glass dosemeters for ‘paired dosemeter’ together with introduction of a simple algorithm may be a promising method to improve the response in the energy range below 20 keV.
Internal dosimetric analyser to assist routine, confirmatory and special radiobioassays
Authors: Hunt John G , Capote-Cuellar Antonio , Suárez Rodolfo Cruz , Kenny Patrick , Lafranco Gábor , Hajek Michael
Published: October 2023

The IAEA Radiation Safety Technical Services Laboratory has developed and validated an Internal Dosimetric Analyser (IDA) software tool to facilitate access to dosimetric data and perform calculations related to individual monitoring for intakes of radionuclides and occupational radiation protection. IDA serves to correlate measurements from routine, confirmatory and special internal monitoring with data obtained from the Occupational Intakes of Radionuclides series of recommendations published by the International Commission on Radiological Protection. The purpose of IDA is to keep the internal dosimetry data in the background and allow the dosimetrist to make the necessary calculations to be able to decide (1) whether the bioassay method and monitoring period are appropriate for routine, confirmatory or special monitoring; (2) whether the method and period will allow the recording level to be detected; (3) whether previous intakes are contributing to the current measurement; and (4) whether measurement uncertainties affect the dose assessment.
EURADOS project on the impact of the proposed ICRU operational dose quantities
Authors: Gilvin Phil , Caresana Marco , Bottollier-Depois Jean-Francois , Chumak Vadim , Clairand Isabelle , Eakins Jonathan , Ferrari Paolo , Hupe Oliver , Olko Pawel , Röttger A , Tanner Rick , Vanhavere Filip , Bakhanova Elena , Bandalo Vedran , Ekendahl Daniela , Hödlmoser Herbert , Matthiä Daniel , Reitz Günther , Latocha Marcin , Beck Peter , Thomas David , Behrens Rolf
Published: October 2023

Following the publication of the joint The International Commissions on Radiation Units and Measurements (ICRU) and on Radiological Protection (ICRP) report on new operational quantities for radiation protection, the European Dosimetry Group (EURADOS) have carried out an initial evaluation. The EURADOS report analyses the impact that the new quantities will have on: radiation protection practice; calibration and reference fields; European and national regulation; international standards and, especially, dosemeter and instrument design. The task group included experienced scientists drawn from across the various EURADOS working groups.