bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthetic hematocrit from virtual non-contrast images for myocardial extracellular volume evaluation with photon-counting detector CT
Authors: Mergen Victor , Ehrbar Nicolas , Moser Lukas J. , Harmes Johannes C. , Manka Robert , Alkadhi Hatem , Eberhard Matthias 
Published: June 2024

Abstract
Objectives
To assess the accuracy of a synthetic hematocrit derived from virtual non-contrast (VNC) and virtual non-iodine images (VNI) for myocardial extracellular volume (ECV) computation with photon-counting detector computed tomography (PCD-CT).

Materials and methods
Consecutive patients undergoing PCD-CT including a coronary CT angiography (CCTA) and a late enhancement (LE) scan and having a blood hematocrit were retrospectively included. In the first 75 patients (derivation cohort), CCTA and LE scans were reconstructed as VNI at 60, 70, and 80 keV and as VNC with quantum iterative reconstruction (QIR) strengths 2, 3, and 4. Blood pool attenuation (BPmean) was correlated to blood hematocrit. In the next 50 patients (validation cohort), synthetic hematocrit was calculated using BPmean. Myocardial ECV was computed using the synthetic hematocrit and compared with the ECV using the blood hematocrit as a reference.

Results
In the derivation cohort (49 men, mean age 79 ± 8 years), a correlation between BPmean and blood hematocrit ranged from poor for VNI of CCTA at 80 keV, QIR2 (R2 = 0.12) to moderate for VNI of LE at 60 keV, QIR4; 70 keV, QIR3 and 4; and VNC of LE, QIR3 and 4 (all, R2 = 0.58). In the validation cohort (29 men, age 75 ± 14 years), synthetic hematocrit was calculated from VNC of the LE scan, QIR3. Median ECV was 26.9% (interquartile range (IQR), 25.5%, 28.8%) using the blood hematocrit and 26.8% (IQR, 25.4%, 29.7%) using synthetic hematocrit (VNC, QIR3; mean difference, −0.2%; limits of agreement, −2.4%, 2.0%; p = 0.33).

Conclusion
Synthetic hematocrit calculated from VNC images enables an accurate computation of myocardial ECV with PCD-CT.

Clinical relevance statement
Virtual non-contrast images from cardiac late enhancement scans with photon-counting detector CT allow the calculation of a synthetic hematocrit, which enables accurate computation of myocardial extracellular volume.

Key Points

Blood hematocrit is mandatory for conventional myocardial extracellular volume computation.

Synthetic hematocrit can be calculated from virtual non-iodine and non-contrast photon-counting detector CT images.

Synthetic hematocrit from virtual non-contrast images enables computation of the myocardial extracellular volume.
In vitro and in vivo studies on exogenous polyamines and α-difluoromethylornithine to enhance bone formation and suppress osteoclast differentiation
Authors: Lee Chien-Ching , Chuang Chia-Chun , Chen Chung-Hwan , Huang Yuan-Pin , Chang Chiao-Yi , Tung Pei-Yi , Lee Mon-Juan 
Published: June 2024

AbstractExogenous polyamines, including putrescine (PUT), spermidine (SPD), and spermine (SPM), and the irreversible inhibitor of the rate-limiting enzyme ornithine decarboxylase (ODC) of polyamine biosynthesis, α-difluoromethylornithine (DFMO), are implicated as stimulants for bone formation. We demonstrate in this study the osteogenic potential of exogenous polyamines and DFMO in human osteoblasts (hOBs), murine monocyte cell line RAW 264.7, and an ovariectomized rat model. The effect of polyamines and DFMO on hOBs and RAW 264.7 cells was studied by analyzing gene expression, alkaline phosphatase (ALP) activity, tartrate-resistant acid phosphatase (TRAP) activity, and matrix mineralization. Ovariectomized rats were treated with polyamines and DFMO and analyzed by micro computed tomography (micro CT). The mRNA level of the early onset genes of osteogenic differentiation, Runt-related transcription factor 2 (Runx2) and ALP, was significantly elevated in hOBs under osteogenic conditions, while both ALP activity and matrix mineralization were enhanced by exogenous polyamines and DFMO. Under osteoclastogenic conditions, the gene expression of both receptor activator of nuclear factor-κB (RANK) and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) was reduced, and TRAP activity was suppressed by exogenous polyamines and DFMO in RAW 264.7 cells. In an osteoporotic animal model of ovariectomized rats, SPM and DFMO were found to improve bone volume in rat femurs, while trabecular thickness was increased in all treatment groups. Results from this study provide in vitro and in vivo evidence indicating that polyamines and DFMO act as stimulants for bone formation, and their osteogenic effect may be associated with the suppression of osteoclastogenesis.
Prevalence and risk factors of extended-spectrum beta-lactamase producing E. coli causing urinary tract infections in Iceland during 2012–2021
Authors: Halldórsdóttir Anna Margrét , Hrafnkelsson Birgir , Einarsdóttir Kristjana , Kristinsson Karl G. 
Published: June 2024

Abstract
Purpose
To investigate the association of potential risk factors for urinary tract infections (UTI) caused by E. coli producing ESBL vs. not producing ESBL in Iceland.

Methods
Observational, case-control study including a cohort of 27,747 patients (22,800 females, 4,947 males; 1207 cases, 26,540 controls) of all ages with UTI caused by E. coli in 2012 to 2021 at the clinical microbiology laboratory covering about 2/3 of the Icelandic population. Clinical patient data was obtained from three national databases. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) as a measure of association between ESBL and exposure variables.

Results
The proportion of samples with ESBL-producing E. coli increased during the study period, from 2.6% in 2012 to 7.6% in 2021 (p < 0.001). ESBL-positive strains were detected in 1207 individuals (4.4%), 905 females (4.0%) and 302 males (6.1%). The following risk factors were identified: Male sex, higher age, institution type (hospital, nursing home), hospital-associated UTI, Charlson comorbidity index score ≥ 3, history of cystitis or hospitalization in the past year, and prescriptions for certain antibiotics or proton pump inhibitors (PPIs: OR 1.51) in the past half year. The antibiotic associated with the highest risk was ciprofloxacin (OR 2.45).

Conclusion
The prevalence of UTIs caused by ESBL-producing E. coli has been increasing in Iceland. The strongest risk factors for ESBL production were previous antibiotic use, especially ciprofloxacin, and previous PPI use, both considered to be overprescribed. It is important to promote the prudent use of these drugs.
Security analysis of the ISO standard $$\textsf{OFB}$$-$$\textsf{DRBG}$$
Authors: Chung Woohyuk , Kim Hwigyeom , Lee Jooyoung , Lee Yeongmin 
Published: June 2024

AbstractDeterministic random bit generators (DRBGs) are essential tools in modern cryptography for generating secure and unpredictable random numbers. The ISO DRBG standards provide guidelines for designing and implementing DRBGs, including four algorithms: $$\textsf{HASH}\text {-}\textsf{DRBG}$$

HASH
-
DRBG

, $$\textsf{HMAC}\text {-}\textsf{DRBG}$$

HMAC
-
DRBG

, $$\textsf{CTR}\text {-}\textsf{DRBG}$$

CTR
-
DRBG

, and $$\textsf{OFB}\text {-}\textsf{DRBG}$$

OFB
-
DRBG

. While security analyses have been conducted for the former three algorithms, there is a lack of specific security analysis for the $$\textsf{OFB}$$
OFB
-$$\textsf{DRBG}$$
DRBG
algorithm. We prove its security in the robustness security framework that has been used to analyze $$\mathsf {CTR\text {-}DRBG}$$

CTR
-
DRBG

by Hoang and Shen at Crypto 2020. More precisely, we prove that $$\textsf{OFB}$$
OFB
-$$\textsf{DRBG}$$
DRBG
provides $$O(\min \left\{ \frac{\lambda }{3}, \frac{n}{2} \right\} )$$

O
(
min

λ
3

,

n
2

)

-bit security, including ideal cipher queries, where $$\lambda $$
λ
and n denote the lower bound of min-entropy and the size of the underlying block cipher, respectively. The proof strategy is to transform the robustness game of $$\textsf{OFB}$$
OFB
-$$\textsf{DRBG}$$
DRBG
into an indistinguishability game and then apply the H-coefficient technique to upper bound the distinguishing advantage.
Conserving integration of multibody systems with singular and non-constant mass matrix including quaternion-based rigid body dynamics
Authors: Kinon Philipp L. , Betsch Peter 
Published: June 2024

Abstract
Mechanical systems with singular and/or configuration-dependent mass matrix can pose difficulties to Hamiltonian formulations, which are the standard choice for the design of energy-momentum conserving time integrators. In this work, we derive a structure-preserving time integrator for constrained mechanical systems based on a mixed variational approach. Livens’ principle (or sometimes called Hamilton–Pontryagin principle) features independent velocity and momentum quantities and circumvents the need to invert the mass matrix. In particular, we take up the description of rigid body rotations using unit quaternions. Using Livens’ principle, a new and comparatively easy approach to the simulation of these problems is presented. The equations of motion are approximated by using (partitioned) midpoint discrete gradients, thus generating a new energy-momentum conserving integration scheme for mechanical systems with singular and/or configuration-dependent mass matrix. The derived method is second-order accurate and algorithmically preserves a generalized energy function as well as the holonomic constraints and momentum maps corresponding to symmetries of the system. We study the numerical performance of the newly devised scheme in representative examples for multibody and rigid body dynamics.
Novel exact solutions to the perturbed Gerdjikov–Ivanov equation
Authors: Youssoufa Mati , Gulsen Selahattin , Hashemi Mir Sajjad , Rezapour Shahram , Inc Mustafa 
Published: June 2024

AbstractThis paper introduces the Nucci reduction method, a novel and efficient approach for deriving exact solutions to the perturbed Gerdjikov–Ivanov equation, offering a significant advancement in the field. The suggested technique involves transforming the equation into real and imaginary components prior to application. We successfully obtained four distinct exact and explicit solutions, along with the corresponding first integrals. Explanations and presentations of solutions are given in a logical manner. We derive an analytical expression for the instability gain and examine its key features using linear stability analysis. Finally, we compare the correctness of the analytical and numerical solutions. We demonstrate the robustness and stability of solitary waves through numerical simulations.
Measuring Political Institutions in the Long Run: A Latent Variable Analysis of Political Regimes, 1810–2018
Authors: Garoupa Nuno , Spruk Rok 
Published: June 2024

AbstractIn this article, latent variable analysis is used to construct hybrid measure of political development based on the plausible common variation between objective and subjective indicators of political institutions. For a sample of 167 countries for the period 1810–2018, we chart long-term paths of political development. Our empirical strategy attempts to overcome the existing potential bias in the measures of democracy in the long run by extracting the institutional characteristics of political regimes, voter turnout, expert-based assessments and electoral outcomes into two latent indices of political development that can be compared both across space and time. The evidence reveals the remarkable persistence of multiple peaks in the world distribution of political development and uncovers contrasting long-term trajectories across countries traditionally featured in the political economy literature. Our findings add to the current debate about measurement of democratic backsliding.
Plasma oxytocin levels in response to glucagon in patients with arginine vasopressin deficiency (central diabetes insipidus) and healthy controls
Authors: Atila Cihan , Mekkattu Shalini , Murugesu Rakithan , Gaisl Odile , Varghese Nimmy , Eckert Anne , Christ-Crain Mirjam 
Published: June 2024

Abstract
Purpose
We recently demonstrated an additional oxytocin (OT) deficiency in patients with arginine vasopressin (AVP) deficiency (central diabetes insipidus) by using 3,4-methylenedioxy-methamphetamine (MDMA) as a novel provocation test. However, the implication of the MDMA provocation test in clinical practice might be challenging. Glucagon effectively stimulates vasopressinergic neurons with a strong increase in plasma copeptin. We therefore hypothesized that this provocation test might also stimulate OT.

Methods
This is a predefined secondary analysis of a prospective double-blind, randomised, placebo-controlled cross-over trial involving ten patients with AVP deficiency and ten sex- and body-mass index-matched healthy participants at the University Hospital Basel, Switzerland. Each participant underwent the glucagon test (s.c. injection of 1 mg glucagon) and placebo test (s.c. injection of 0.9% normal saline). Plasma OT levels were measured at baseline, 60, 120 and 180 min after injection. The primary objective was to determine whether glucagon stimulates OT and whether OT levels differ between patients with AVP deficiency and healthy participants. The primary outcome (maximum change in OT within 180 min) was compared between groups and conditions using a linear mixed effects model.

Results
In healthy participants, the median OT at baseline was 82.7 pg/ml [62.3–94.3] and slightly increased to a maximum of 93.3 pg/ml [87.2–121.1] after injection of glucagon, resulting in a change increase of 24.9 pg/ml [5.1–27.8]. Similarly, in patients with AVP deficiency, the median OT at baseline was 73.9 pg/ml [65.3–81.6] and slightly increased after glucagon injection to 114.9 pg/ml [70.9–140.9], resulting in a change increase of 36.8 pg/ml [–2.2 to 51.2]. The results from the mixed model showed no effect between glucagon compared to placebo on OT (difference: –0.5 pg/ml; 95%-CI [–25, 24]; p = 0.97) and no significant treatment-by-group interaction effect between patients compared to healthy participants (interaction: 28 pg/ml; 95%-CI [–7, 62]; p = 0.13).

Conclusion
We found no effect of glucagon on plasma OT levels and no difference between patients with AVP deficiency and healthy participants.
Decoding the Journey Towards Digital Work Processes. Reflections on the Impact of Agile Working on Knowledge Hiding and Knowledge Sharing
Authors: Cirielli De Mola Italo Giuseppe , Napoli Luigi , Giancotti Fernando , Caputo Francesco 
Published: June 2024

AbstractOrganizations, communities, and socio-economic entities are rapidly changing in response to the consequences of the COVID-19 pandemic. Increasing attention is reserved for the opportunities offered by digitalization to identify different approaches for performing “traditional activities” in a new way. In such a scenario, Agile Working is contributing to reframing socio-economic entities, and new challenges are emerging in terms of human resources management. With the aim of enriching the current debate about the impact of Agile Working on socio-economic processes and organizations, this paper adopts the interpretative lens provided by Knowledge Management and Systems Thinking for depicting a conceptual model able to support both researchers and practitioners in understanding how digital work processes can influence knowledge hiding and knowledge sharing inside organized entities.
Epidemiology and risk factors of community-acquired pneumonia in patients with different causes of immunosuppression
Authors: Reichel Fabian , Tesch Falko , Berger Saskia , Seifert Martin , Koschel Dirk , Schmitt Jochen , Kolditz Martin 
Published: June 2024

AbstractImmunosuppression constitutes a significant risk for community-acquired pneumonia (CAP). Nevertheless, specific causes of immunosuppression and their relevance for incidence, etiology and prognosis of CAP are insufficiently investigated.We conducted a population-based cohort study within a statutory health insurance in Germany from 2015 to 2018. CAP was retrieved by ICD-10-GM codes. Episodes of immunosuppression were identified by coded conditions (hematologic neoplasms, stem cell or organ transplantation, neutropenia, HIV, primary immunosuppressive syndromes) or treatments (immunosuppressants, antineoplastic drugs, systemic steroids). Endpoints were defined as occurrence of CAP (primary), hospitalization, 30-day mortality and CAP associated with rare pathogens. Our analysis utilized the Andersen-Gill model adjusted for sex, age, level of long-term care, vaccination status, community type and comorbidities.942,008 individuals with 54,781 CAPs were included (hospitalization 55%, 30-day mortality 14.5%). 6% of individuals showed at least one episode of immunosuppression during the study period with systemic steroids (39.8%) and hematologic neoplasms (26.7%) being most common. Immunosuppression was recorded in 7.7% of CAPs. Besides classical risk factors such as age and level of long-term care, immunosuppressed patients were most prone to CAP (HR 2.4[2.3–2.5]) and consecutive death (HR 1.9[1.8–2.1]). Organ and stem cell transplantation (HR 3.2[2.6–4.0] and 2.8[2.1–3.7], respectively), HIV (HR 3.2[1.9–5.4]) and systemic steroids (> 20 mg prednisone daily dose equivalent (HR 2.7[2.4–3.1])) showed the highest risk for contracting CAP. CAP by rare pathogens was strongly associated with immunosuppression (HR 17.1[12.0–24.5]), especially HIV (HR 34.1[7.6–153]) and systemic steroids (HR 8.2[4.6–14.8]).Our study elucidates the relevance of particular immunosuppressive conditions including systemic steroids for occurrence and prognosis of CAP.
Using archived magnetotelluric data for geologic interpretation in the Transdanubian Region
Authors: Szebenyi Renáta , Kiss János , Héja Gábor Herkules 
Published: June 2024

AbstractWe provide a key magnetotelluric section, composed of archived magnetotelluric data along a NW-SE profile in Transdanubia, Hungary. For the interpretation of the key section, observations from raw magnetotelluric data and inversion results were used. In addition, other geophysical-geological information was also considered to confirm the conclusions based on the electrical resistivity sections. All this information was combined to identify the main structural lines and geologic units along the profile. Main structural lines observed on the resistivity sections are the Alpokalja line, Rába line, Balaton line, Kapos line, and Mecsekalja line. Geologic units that can be delineated due to their resistivity contrast include the Lower and Upper Austroalpine Units, the Transdanubian Range Unit, the Mid-Hungarian Megaunit, the Tisza Megaunit and sedimentary rocks filling the sub-basins of the Miocene Pannonian back-arc basin. The inversion results of the transverse magnetic (TM) polarization mode and the phase-depth sections of the raw data were found to be the most suitable for detecting the morphology and identifying the depth of the Pre-Cenozoic basement along the profile.
Spatial variability of geotechnical parameters of lateritic gravels in an Olama–Ngomedzap road section in a humid tropical area (Cameroon)
Authors: Mveng Marie Diane Marquise Ngono , Zame Philémon Zo’o , Bayamack Joel Fabrice Nyemb , Bisso Dieudonné , Atangana Joseph Quentin Yene 
Published: June 2024

AbstractSearching for borrow pits often used during civil engineering constructions is an important step that requires a lot of time and money. The nature of the parent rock, climate, topography, vegetation and time influence the formation of lateritic gravels with different geotechnical properties within the same region. The present study aims at finding the spatial variability of geotechnical parameters of lateritic gravels from two different deposits using a variogram and statistical analysis. Out of 122 lateritic gravel samples collected, 69 were from underdeveloped lithic ferrallitic soils (LFS) and 53 from under developed non-lithic ferrallitic soils (NLFS). The mean values of the coefficient of variation (CV) shows that the geotechnical parameters of LFS-derived lateritic gravels are more dispersed than those developed on NLFS. The fines content, plasticity index (PI) and Californian bearing ratio (CBR) variograms observed mainly in the North and NNE parts of the study area, suggest that, the lateritic gravels in this area have average to good geotechnical characteristics. The principal component analysis (PCA) indicates that the CBR and the maximum dry density (MDD) are inversely related to the optimum moisture content (OMC). The discriminant factor analysis (DFA) coupled to the ascending hierarchical classification (AHC) shows three families of lateritic gravels: (1) class 1/3, lateritic gravels characterized by MDD, CBR, consistency index (CI), gravels content, and plastic limit (PL); (2) class 2/3, lateritic gravels characterized by fines content, and maximum grain diameter (Dmax) and, (3) class 3/3, lateritic gravels characterized by OMC, liquid limit (LL), PI, PL, and fines content, that fit for road construction.
Stochastic Optimization for Long-Term Planning of a Mining Complex with In-Pit Crushing and Conveying Systems
Authors: Findlay Liam , Dimitrakopoulos Roussos 
Published: June 2024

AbstractSemi-mobile in-pit crushing and conveying (IPCC) systems can help reduce truck haulage in open-pit mines by bringing the crusher closer to the excavation areas. Optimizing a production schedule with semi-mobile IPCC requires integrating extraction sequence, destination policy, crusher relocation, conveyor layout, and truck fleet investment decisions. A mining complex with multiple mines and IPCC systems should be optimized simultaneously to find an optimal schedule for the entire value chain. An integrated stochastic optimization framework is proposed to produce long-term production schedules for mining complexes using multiple semi-mobile IPCC systems. The optimization model has flexibility to select the crusher locations and conveyor routes from anywhere inside the pits. The framework uses simulated orebody realizations to consider multi-element grade uncertainty and manage associated risk. A hybrid metaheuristic solution approach based on simulated annealing and evolutionary algorithms is implemented. The method is demonstrated using an iron ore mining complex.
Metaverse ethics: exploring the social implications of the metaverse
Authors: Yasuda Arisa 
Published: June 2024

AbstractThe emergence of the metaverse transforms the way humans interact with computers; the metaverse brings about a new form of human-computer interaction that is more immersive, intuitive, and seamless. In the present paper we thus aim to elucidate the role of human-computer interactions in the age of the metaverse. New forms of human-computer interaction via the metaverse are beneficial for humans in many ways; at the same time, however, there are new types of social issues that are emerging as the metaverse develops and that need to be taken seriously. Specifically, we focus upon issues such as privacy, surveillance capitalism, cyber-syndromes, amplifications of other social problems, environmental problems, and discuss what regulations would be appropriate in order to balance the adequate development of the metaverse with the safety and security of it that is required for social good, in particular for sustainable development goals. We finally propose ethical design principles for the sustainable metaverse in order to address the aforementioned and other social issues.