bluuebunny/crossref_metadata_2025 huggingface dataset:
Shifting perspectives: How scrutiny shapes the relationship between CEO gender and acquisition activity
Authors: Gamache Daniel L. , Devers Cynthia E. , Klein Felice B. , Hannigan Timothy
Published: June 2023

Research Summary

Several upper echelons studies have found that firms led by female executives are less likely to engage in risky endeavors than those led by male top executives. We argue that conceptualizing female CEOs as universally conservative decision‐makers may paint too simplistic a picture and that the impact of CEO gender on strategic decision‐making may vary significantly depending on the given situation CEOs are experiencing. We integrate executive job demands and gender research to propose that scrutiny will exhibit differential effects on female and male CEOs' acquisition activity. We show that in high‐scrutiny contexts, the difference between male and female CEO acquisition activity disappears. In contrast, in low‐scrutiny contexts, the difference between male and female CEOs' acquisition activity is exaggerated.

Managerial Summary

Substantial research has shown that female executives acquire at a lower rate than male executives. We argue that viewing female CEOs as universally conservative decision‐makers may paint too simplistic a picture and that the impact of CEO gender on strategic decision‐making may vary significantly depending on the given situation CEOs are experiencing. In particular, we argue and find that in high‐scrutiny contexts, the difference between male and female CEO acquisition activity disappears. This research suggests that managers should consider the impact of environmental context—especially the role of scrutiny—when considering the risk propensity of female leaders.
Directly Cross‐Linked Conjugated Polymer Donor Enables Efficient Polymer Solar Cells with Extraordinary Mechanical Robustness
Authors: Ye Linglong , Yang Yinuo , Liu Chunhui , Duan Xiaopeng , Wang Shijie , Li Wei , Sun Xiaobo , Wang Tao , Ma Wei , Li Weiwei , Sun Yanming
Published: June 2023

A cross‐linking strategy can result in a three‐dimensional network of interconnected chains for the copolymers, thereby improving their mechanical performance. In this work, a series of cross‐linked conjugated copolymers, named PC2, PC5, and PC8, constructed with different ratios of monomers are designed and synthesized. For comparison, a random linear copolymer, PR2 is also synthesized based on the similar monomers. When blended with Y6 acceptor, the cross‐linked polymers PC2, PC5, and PC8‐based polymer solar cells (PSCs) achieve superior power conversion efficiencies (PCEs) of 17.58%, 17.02%, and 16.12%, respectively, which are higher than that (15.84%) of the random copolymer PR2‐based devices. Moreover, the PCE of PC2:Y6‐based flexible PSC retains ≈88% of the initial efficiency value after 2000 bending cycles, overwhelming the PR2:Y6‐based device with the remaining 12.8% of the initial PCE. These results demonstrate that the cross‐linking strategy is a feasible and facile approach to developing high‐performance polymer donors for the fabrication of flexible PSCs.
Enabling Specific Benzene Oxidation by Tuning the Adsorption Behavior on Au Loaded MgAl Layered Double Hydroxides
Authors: Shen Tianyang , Song Ziheng , Li Jiaxin , bai Sha , Liu Guihao , Sun Xiaoliang , Li Shaoquan , Chen Wei , Zheng Lirong , Song Yu‐Fei
Published: June 2023

Direct and selective oxidation of benzene to phenol is a long‐term goal in industry. Although great efforts have been made in homogenous catalysis, it still remains a huge challenge to drive this reaction via heterogeneous catalysts under mild conditions. Herein, a single‐atom Au loaded MgAl‐layered double hydroxide (Au1‐MgAl‐LDH) with a well‐defined structure, in which the Au single atoms are located on the top of Al3+ with Au‐O4 coordination as revealed by extended x–ray–absorption fine–structure (EXAFS)and density–functional theory (DFT)calculation is reported. The photocatalytic results prove the Au1‐MgAl‐LDH is capable of driving benzene oxidation reaction with O2 in water, and exhibits a high selectivity of 99% for phenol. While contrast experiment shows a ≈99% selectivity for aliphatic acid with Au nanoparticle loaded MgAl‐LDH (Au‐NP‐MgAl‐LDH). Detailed characterizations confirm that the origin of the selectivity difference can be attributed to the profound adsorption behavior of substrate benzene with Au single atoms and nanoparticles. For Au1‐MgAl‐LDH, single Au‐C bond is formed in benzene activation and result in the production of phenol. While for Au‐NP‐MgAl‐LDH, multiple AuC bonds are generated in benzene activation, leading to the crack of CC bond.
Unsteady flow of micropolar fluid on a magnetized sheet: Effects of magnetic and microrotation parameters on wall couple stress and skin friction
Authors: Ahmad Adeel , Ishaq Airal , Athar Maria , Anjum Junaid , Nawaz Rab
Published: June 2023

In this study, we investigate the unsteady flow of a micropolar fluid past a magnetized stretchable/shrinkable sheet. Our research aims to analyze the effects of magnetic field, moving slit, and various parameters on the velocity, magnetic, and microrotation profiles of the fluid. By applying the Blasius–Rayleigh–Stokes variable, we derive ordinary differential equations from the partial differential equations that define the problem. We solve the transformed set of equations using the shooting method and obtain dual solutions. Our findings indicate that skin friction decreases with increasing values of the microrotation parameter and magnetic interaction parameter. We also observe that the magnetic interaction parameter enhances the microrotation of molecules. Overall, our study provides valuable insights into the behavior of unsteady flows in micropolar fluids and sheds light on the impact of various parameters on dual solutions.
Introduction: Historicizing and Spatializing Global Slavery
Authors: Pargas Damian A.
Published: June 2023

The introduction to this volume explains the condition of slavery (including its definition and its place at the far end of a broad spectrum of coercion and unfreedom); illuminates conceptual and methodological choices; and discusses the layout and main intentions of the handbook. In particular it discusses how scholars approach the study of slavery, as well as some common themes in global slavery scholarship. It also underscores the intention of this volume to both historicize and spatialize slavery—i.e., to historicize it by moving beyond linear stories that trace slavery from Graeco-Roman antiquity and end with transatlantic slavery and abolition; and to spatialize it by recentering the geography of slavery, illuminating regional contexts of slavery around the world.
Slavery in the Ottoman Empire
Authors: Özkoray Hayri Gökşin
Published: June 2023

This chapter analyzes Ottoman slavery as an institution in order to provide readers with insights into how Ottoman society both benefited from slavery and became largely defined by it. The topic will be examined by illuminating the aspects of entry into slavery, extraction of slave labor, and exits from slavery, arguing that these three phases were cyclical rather than gradually evolutionist.
Slavery in Chosŏn Korea
Authors: Kim Sun Joo
Published: June 2023

Chosŏn Korea (1392–1910) was one of the most enduring slave societies in world history. This chapter discusses how slavery as an institution evolved during the Chosŏn dynasty, paying particular attention to the emergence of a large-scale slave society, the socio-economic values of slavery within the social hierarchy, slaves’ legal status and their agency in managing their lives, various means through which slaves achieved their freedom, and the socio-economic, legal, and moral factors that contributed to the dissolution of slavery.
Mesopotamian Slavery
Authors: Richardson Seth
Published: June 2023

A survey of Mesopotamian slavery provides an opportunity to evaluate how foundational or institutional the practice was in its earliest known forms. The entry to and exit from slavery were relatively asystematic, the status often ended up being temporary, and the functions and status of slaves are difficult to distinguish from those of other persons (e.g., servants and dependents) who also performed labor under coercion. This chapter considers these aspects as well as developments and changes in Mesopotamian slavery in the Old Babylonian period (ca. 2000–1600 BCE), focusing on this specific historical period as a model to comment on slavery in cuneiform culture as a whole (which lasted from ca. 3300 to 300 BCE).
Maritime Passages in the Indian Ocean Slave Trade
Authors: Machado Pedro
Published: June 2023

Enslavement as a process was complex and multilayered, often encompassing experiences of dislocation and displacement, as individuals were taken from their homes to destinations that could be thousands of miles away. This chapter considers the range of experiences that both African and Asian slaves endured in the Indian Ocean in the eighteenth and nineteenth centuries during periods of intensified exchange of captives between the interiors, coasts and islands scattered across the ocean. While the moment of capture or bondage signaled the beginning of a new unfree state and social position, the experience of enslavement did not necessarily end at that moment; rather, it initiated a process whose trajectories could be expansive and involve multiple stages (and geographies) that shaped the contours of an unfree existence in the ocean.
Slavery in Francophone West Africa
Authors: Rossi Benedetta
Published: June 2023

Multiple forms of labor coercion were common in West Africa in the first half of the twentieth century. This chapter focuses on two of them: one, based on interior slavery, was rooted in the longue durée of regional history. The other, colonial forced labor, was exogenous and introduced by European colonialists between the mid-nineteenth and the early twentieth century. In Tahoua, the region of today’s Republic of Niger that this chapter focuses on, these two forms of coerced labor co-existed. In 1905 France abolished indigenous slavery in its recently acquired African territories and concurrently introduced a regime of compulsory labor for the building and maintenance of colonial infrastructure. In spite of French legal abolition, indigenous slavery did not die out, but started being contested and resisted more effectively by those who had been enslaved. Those formerly enslaved to local slaveowners and their descendants were also the first to be forcibly recruited to carry out construction work on colonial worksites. These two regimes of coerced labor, with different ideological origins, became intertwined and underwent substantial changes throughout the twentieth century. Their legacies have continued influencing labor relations and forms of personal dependence into the present day.
Slavery in the Roman Empire
Authors: Lenski Noel
Published: June 2023

The Roman Empire developed one of the largest and most economically and culturally integrated systems of slavery in world history. It thrived on a remarkably robust supply stream that included enslavement by birth, capture, sale from foreign and domestic sources, the reclaiming of exposed infants, and—in late antiquity—self-sale, child sale, and debt bondage. Enslavement was imposed upon people from all regions, inside and outside the empire, and was never inflicted exclusively on a particular racial or ethnic group. Those enslaved to Rome worked in agriculture, industry, service, and even knowledge production, allowing them to be the primary workforce behind the generation of elite wealth. Escape from slavery could at times involve resistance, including everything from open revolt to flight, but Roman society was also remarkably generous with manumission. This and many other features reflect a hybridity between ancient patterns of captive integration and modern habits of slave exclusion.
Slavery in the Black Sea Region
Authors: Barker Hannah
Published: June 2023

During the medieval period, people in the Black Sea region both owned slaves and exported them. The majority of Black Sea slaves were not born into that status; they became enslaved either through capture or sale. Once enslaved, they might be kept locally for domestic and sexual service, or they might be commodified and sold into long-distance commercial networks that extended east toward China and west toward the Mediterranean. An end to enslavement could not be taken for granted: some slaves were ransomed, some were individually manumitted, some escaped, but many died in slavery.
Introduction: A Legal Geography of Property Rights in Land
Authors: Byer Amanda
Published: June 2023

The opening chapter sets out the aim of the work, which is to examine the common law concept of property in relation to land using a landscape lens. The chapter distinguishes this research from other genealogies of property by emphasising the use of the legal geography methodology to critique property in terms of its relation to space. The chapter summarises the main features of modern land law. The book’s structure is outlined, beginning with an exploration of property’s roots in landscape, an investigation of the development of the classic hallmarks of property through a legal geographical analysis of classic property theory, a discussion of property’s linkages to spatial injustice and a critique of progressive property’s potential to challenge the ownership paradigm in property law.
Zero modes of fermions trapped by giant vortices
Authors: Gates Logan , Penin Alexander A.
Published: June 2023

Abstract

Zero-energy solutions of the Dirac equation for the fermions bound to giant vortices of large winding number n are studied in the abelian Higgs and Chern-Simons Higgs models. The case of Jackiw-Rossi theory of the Majorana states in topological superconductors is discussed in detail. By expanding in inverse powers of n we find an analytic result for asymptotically all n solutions required by the index theorem. In the abelian Higgs model the zero modes fill the vortex core and reveal a universal structure independent of fine details of the gauge and scalar field interactions which, in particular, determines the general properties of the large-n superconducting cosmic strings. On the contrary, for the Chern-Simons Higgs vortices the zero modes are localized on the core boundary and the explicit solution is obtained for the supersymmetric couplings in a self-dual background.
SL(2, R) × U(1) symmetry and quasinormal modes in the self-dual warped AdS black hole
Authors: Chen Yuan , Guo Wei , Shi Kai , Zhang Hongbao
Published: June 2023

Abstract

The algebraic approach to the spectrum of quasinormal modes has been made as simple as possible for the BTZ black hole by the strategy developed in [16]. By working with the self-dual warped AdS black hole, we demonstrate in an explicit way that such a strategy can be well adapted to those warped AdS balck holes with the SL(2, R) × U(1) isometry. To this end, we first introduce two associated tensor fields with the quadratic Casimir of SL(2, R) × U(1) Lie algebra in the self-dual warped AdS black hole and show that they correspond essentially to the metric and volume element up to a constant prefactor, respectively. Then without appealing to any concrete coordinate system, we can further show that the solutions to the equations of motion for the scalar, vector, spinor fields all fall into the representations of the SL(2, R) × U(1) Lie algebra by a purely abstract tensor and spinor analysis. Accordingly, the corresponding spectrum of quasinormal modes for each fixed azimuthal quantum number can be derived algebraically as the infinite tower of descendants of the highest weight mode of the SL(2, R) Lie subalgebra.
Seismicity and Fault Interaction in the Gulf of Aqaba
Authors: Abdelazim Mona , ElGabry Mohamed N. , Gobashy Mohamed M. , Khalil Mohamed H. , Hussein Hesham M.
Published: June 2023

The Gulf of Aqaba is considered one of the most seismotectonically active regions in the Middle East. This study analyzes the seismic activity from 1983 to 2018 to investigate the spatio-temporal distribution of the events in the Gulf’s three basins. The seismic activity is characterized by conventional mainshock–aftershock sequences and swarm activity. Most activity is located in the Aragonese basin, while the Dakar basin shows less seismic activity. The b-value was calculated for the three basins from the declustered catalogue, representing the fingerprint of the transform fault. Within the Aragonese, three significant earthquakes occurred in 1993, 1995, and 2015 with moment magnitude (Mw) of 5.8, 7.2, and 5.2, respectively. An intermediate seismic quiescence preceded the three earthquakes. The quiescence time for the 1995 earthquake began at the tail of the aftershocks of the 1993 mainshock, suggesting that the two earthquakes were not entirely independent. At the tail of the 1995 earthquake aftershocks, the seismic activity spread across the Gulf, increasing in frequency and decreasing in magnitude. A similar pattern was observed for the seismic quiescence preceding the 2015 mainshock. The occurrence of the three significant and proximal earthquakes in the Aragonese region over a 22-year interval, with the described similarities, suggests a link between these earthquakes. Finally, the Coulomb stress transfer shows that the 1993 source fault seems to increase the stress loading on the 1995 left-lateral strike-slip fault, and the latter would also increase the stress transfer on the 2015 left-lateral strike-slip fault.
Diagnosing Hydro-Mechanical Effects in Subsurface Fluid Flow Through Fractures
Authors: Schmidt Patrick , Steeb Holger , Renner Jörg
Published: June 2023

Hydro-mechanically induced transient changes in fracture volume elude an analysis of pressure and flow rate transients by conventional diffusion-based models. We used a previously developed fully coupled, inherently non-linear numerical simulation model to demonstrate that harmonic hydraulic excitation of fractures leads to systematic overtones in the response spectrum that can thus be used as a diagnostic criterion for hydro-mechanical interaction. The examination of response spectra, obtained from harmonic testing at four different field sites, for the occurrence of overtones confirmed their potential for the hydro-mechanical characterization of tested reservoirs. A non-dimensional analysis identified relative aperture change as the critical system parameter.
Evidenzbasierte Prävention für die psychische Gesundheit von Kindern und Jugendlichen: Der Ansatz „Communities That Care“ (CTC) für Deutschland
Authors: Walter Ulla , Groeger-Roth Frederick , Röding Dominik
Published: June 2023

Intersektorale Zusammenarbeit, Evidenzbasierung und nachhaltige Implementation sind zentrale Herausforderungen in der kommunalen Gesundheitsförderung. Diese adressiert das internationale Präventionssystem „Communities That Care“ (CTC). CTC zielt mit einer systemischen Mehr-Ebenen-Strategie auf die Prävention von Alkohol- und Drogenmissbrauch, Gewalt, Delinquenz, Schulabbruch und depressiven Symptomen bei Heranwachsenden. Das in den USA entwickelte, evidenzbasierte und kosteneffektive Präventionssystem wurde nach Deutschland transferiert; die Kosteneffektivität wird derzeit in einer Replikationsstudie überprüft.

CTC ist empirisch-theoretisch basiert und folgt einem 5‑phasigen Prozessmodell. Wesentlich für die Akzeptanz und evidenzbasierte Durchführung ist die Bildung einer intersektoralen Koalition, deren Mitglieder mehrjährig beratend begleitet und geschult werden. Die Akteur:innen werden befähigt, auf kommunaler Ebene ein Systemveränderungsmodell einzusetzen und langfristig zu implementieren. Ziel ist es, evidenzbasierte Maßnahmen datenbasiert und bedarfsorientiert auszuwählen und unter Berücksichtigung der Kontextbedingungen vor Ort zu implementieren, um Risikofaktoren zu reduzieren, Schutzfaktoren zu fördern und damit die Gesundheit der Heranwachsenden zu verbessern. Validierte Instrumente wie der CTC-Kinder- und Jugendsurvey sowie das Register „Grüne Liste Prävention“ mit evidenzbasierten Programmen unterstützen den Prozess.

CTC integriert als systemische Intervention vorhandene örtliche Strukturen und Organisationen und bindet diese über neue Entscheidungs- und Entwicklungsgremien in den gesamten Prozess ein. Auf diese Weise kann das Potenzial in der Kommune so gut wie möglich genutzt, Ressourcen gebündelt, Kräfte entfaltet und Transparenz hergestellt werden.
Development and validation of an eco-compatible UV–Vis spectrophotometric method for the determination of Cu2+ in aqueous matrices
Authors: Prete Prisco , Iannaccone Davide , Proto Antonio , Tobiszewski Marek , Cucciniello Raffaele
Published: June 2023

Cu2+ are ubiquitous ions in the ecosystem and are responsible of serious environmental pollution. Indeed, the development of sensitive methods for Cu2+ detection is an urgent demand. In this work, we proposed a new spectrophotometric method for Cu2+ determination in different water matrices (distilled water, drinking water, wastewater, and river water). The method employs a bio-based organic ligand namely tetrasodium iminodisuccinate (IDS) able to form a stable complex with the analyte with a maximum absorption at 710 nm. Within the linear range of 6.3–381 mg L−1, the limit of detection (LOD) was determined to be as 1.43 mg L−1. Moreover, the recovery data of the spiked analysis of drinking/river/wastewater water samples were also satisfactory and verified the feasibility of the method for the analysis of Cu2+ in natural conditions. Finally, the AGREE assessment tool was used for a quantitative evaluation of the proposed method and reference method, in agreement with the green analytical chemistry principles. The results showed the lower environmental impact of the proposed method and the suitability of this novel approach for Cu2+ in water matrices.

Graphical abstract
Large prime gaps and probabilistic models
Authors: Banks William , Ford Kevin , Tao Terence
Published: June 2023

We introduce a new probabilistic model of the primes consisting of integers that survive the sieving process when a random residue class is selected for every prime modulus below a specific bound. From a rigorous analysis of this model, we obtain heuristic upper and lower bounds for the size of the largest prime gap in the interval $[1,x]$
[
1
,
x
]
. Our results are stated in terms of the extremal bounds in the interval sieve problem. The same methods also allow us to rigorously relate the validity of the Hardy-Littlewood conjectures for an arbitrary set (such as the actual primes) to lower bounds for the largest gaps within that set.
Host Phylogeny Structures the Gut Bacterial Community Within Galerucella Leaf Beetles
Authors: An Yueqing , Braga Mariana P. , Garcia Sarahi L. , Grudzinska-Sterno Magdalena , Hambäck Peter A.
Published: June 2023

Gut microbes play important roles for their hosts. Previous studies suggest that host-microbial systems can form long-term associations over evolutionary time and the dynamic changes of the intestinal system may represent major driving forces and contribute to insect dietary diversification and speciation. Our study system includes a set of six closely related leaf beetle species (Galerucella spp.) and our study aims to separate the roles of host phylogeny and ecology in determining the gut microbial community and to identify eventual relationship between host insects and gut bacteria. We collected adult beetles from their respective host plants and quantified their microbial community using 16S rRNA sequencing. The results showed that the gut bacteria community composition was structured by host beetle phylogeny, where more or less host-specific gut bacteria interact with the different Galerucella species. For example, the endosymbiotic bacteria Wolbachia was found almost exclusively in G. nymphaea and G. sagittariae. Diversity indicators also suggested that α- and β-diversities of gut bacteria communities varied among host beetle species. Overall, our results suggest a phylogenetically controlled co-occurrence pattern between the six closely related Galerucella beetles and their gut bacteria, indicating the potential of co-evolutionary processes occurring between hosts and their gut bacterial communities.
Evaluation of the Artificial Intelligence Chatbot on Breast Reconstruction and Its Efficacy in Surgical Research: A Case Study
Authors: Xie Yi , Seth Ishith , Rozen Warren M. , Hunter-Smith David J.
Published: June 2023

Background

ChatGPT is an open-source artificial intelligence (AI) chatbot that uses deep learning to produce human-like text dialog. Its potential applications in the scientific community are vast; however, its efficacy on performing comprehensive literature searches, data analysis and report writing in aesthetic plastic surgery topics remains unknown. This study aims to evaluate both the accuracy and comprehensiveness of ChatGPT’s responses to assess its suitability for use in aesthetic plastic surgery research.

Methods

Six questions were prompted to ChatGPT on post-mastectomy breast reconstruction. First two questions focused on the current evidence and options for breast reconstruction post-mastectomy, and remaining four questions focused specifically on autologous breast reconstruction. Using the Likert framework, the responses provided by ChatGPT were qualitatively assessed for accuracy and information content by two specialist plastic surgeons with extensive experience in the field.

Results

ChatGPT provided relevant, accurate information; however, it lacked depth. It could provide no more than a superficial overview in response to more esoteric questions and generated incorrect references. It created non-existent references, cited wrong journal and date, which poses a significant challenge in maintaining academic integrity and caution of its use in academia.

Conclusion

While ChatGPT demonstrated proficiency in summarizing existing knowledge, it created fictitious references which poses a significant concern of its use in academia and healthcare. Caution should be exercised in interpreting its responses in the aesthetic plastic surgical field and should only be used for such with sufficient oversight.

Level of Evidence IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.
Data-driven irrigation scheduling increases the crop water use efficiency of Cabernet Sauvignon grapevines
Authors: Schlank Rochelle , Kidman Catherine M. , Gautam Deepak , Jeffery David W. , Pagay Vinay
Published: June 2023

In the context of water management in agriculture, irrigation scheduling is critically important as it optimises water application to crops and can also target specific production goals. However, there is no consensus on the ideal irrigation scheduling strategy regarding crop water use efficiency (WUEc). In a premium Cabernet Sauvignon vineyard in Coonawarra, South Australia, over three growing seasons, irrigation scheduling strategies based on experience or historical knowledge (‘GROW’ treatment) were compared to data-driven strategies including crop evapotranspiration, and plant and soil water status thresholds to evaluate their effects on leaf- and vine-level WUEs. A final treatment, GROW + , that doubled the GROW level of irrigation was also evaluated in the third season. The WUE metrics were determined at the leaf, vine, and fruit scales as intrinsic WUE (WUEi), crop WUE (WUEc), and carbon isotope ratio (δ13C), respectively. Furthermore, the irrigation strategies were evaluated in the background of two contrasting soil types: Terra Rossa (light clay, well-drained) and Rendzina (heavier clay, poorly drained). Seasonal soil and vine water status, leaf gas exchange, and light interception were measured, and yield components and pruning weights were obtained following harvest. The amount of seasonal irrigation water based on the data-driven strategies was up to 65% lower across both soil types compared with the GROW or GROW + approaches. WUEi and δ13C were largely similar between treatments. However, for vines grown on Terra Rossa soil, little to no yield penalty was observed when data-driven irrigation scheduling was applied, in addition to increased WUEc values of up to 41%. It can be concluded that irrigation scheduling decisions based on data were superior to the conventional irrigation scheduling method on account of reducing irrigation water volume and increasing WUE, particularly in Terra Rossa soils.
Photon-counting CT for diagnosis of acute pulmonary embolism: potential for contrast medium and radiation dose reduction
Authors: Pannenbecker Pauline , Huflage Henner , Grunz Jan-Peter , Gruschwitz Philipp , Patzer Theresa S. , Weng Andreas M. , Heidenreich Julius F. , Bley Thorsten A. , Petritsch Bernhard
Published: June 2023

Objective

To evaluate the image quality of an ultra-low contrast medium and radiation dose CT pulmonary angiography (CTPA) protocol for the diagnosis of acute pulmonary embolism using a clinical photon-counting detector (PCD) CT system and compare its performance to a dual-energy-(DE)-CTPA protocol on a conventional energy-integrating detector (EID) CT system.

Methods

Sixty-four patients either underwent CTPA with the novel scan protocol on the PCD-CT scanner (32 patients, 25 mL, CTDIvol 2.5 mGy·cm) or conventional DE-CTPA on a third-generation dual-source EID-CT (32 patients, 50 mL, CTDIvol 5.1 mGy·cm). Pulmonary artery CT attenuation, signal-to-noise ratio, and contrast-to-noise-ratio were assessed as objective criteria of image quality, while subjective ratings of four radiologists were compared at 60 keV using virtual monoenergetic imaging and polychromatic standard reconstructions. Interrater reliability was determined by means of the intraclass correlation coefficient (ICC). Effective dose was compared between patient cohorts.

Results

Subjective image quality was deemed superior by all four reviewers for 60-keV PCD scans (excellent or good ratings in 93.8% of PCD vs. 84.4% of 60 keV EID scans, ICC = 0.72). No examinations on either system were considered “non-diagnostic.” Objective image quality parameters were significantly higher in the EID group (mostly p < 0.001), both in the polychromatic reconstructions and at 60 keV. The ED (1.4 vs. 3.3 mSv) was significantly lower in the PCD cohort (p < 0.001).

Conclusions

PCD-CTPA allows for considerable reduction of contrast medium and radiation dose in the diagnosis of acute pulmonary embolism, while maintaining good to excellent image quality compared to conventional EID-CTPA.

Clinical relevance statement

Clinical PCD-CT allows for spectral assessment of pulmonary vasculature with high scan speed, which is beneficial in patients with suspected pulmonary embolism, frequently presenting with dyspnea. Simultaneously PCD-CT enables substantial reduction of contrast medium and radiation dose.

Key Points

• The clinical photon-counting detector CT scanner used in this study allows for high-pitch multi-energy acquisitions.

• Photon-counting computed tomography allows for considerable reduction of contrast medium and radiation dose in the diagnosis of acute pulmonary embolism.

• Subjective image quality was rated best for 60-keV photon-counting scans.
The role of MRI in the prenatal diagnosis and classification of fetal microtia
Authors: Zhang Xiaodan , Zheng Weizeng , Feng Yan , Yu Na , Qin Jiale , Li Kui , Yan Guohui , Zou Yu , Li Baohua
Published: June 2023

Objective

To investigate the role of MRI in the diagnosis and classification of fetal microtia.

Methods

Ninety-five fetuses with suspected microtia based on ultrasound and MRI performed within 1 week were enrolled in this study. The diagnosis based on MRI was compared with postnatal diagnosis. Among the microtia cases suspected on the basis of MRI, mild and severe cases were further classified. In addition, external auditory canal (EAC) atresia was evaluated by MRI in 29 fetuses with a gestational age > 28 weeks, and the accuracy of MRI in the diagnosis and classification of microtia was determined.

Results

Of 95 fetuses, 83 were considered to have microtia on the basis of MRI, 81 were confirmed to have microtia, and 14 were found to be normal according to postnatal diagnosis. Among 190 external ears in 95 fetuses, 40 ears were suspected to have mild microtia, and 52 ears were suspected to have severe microtia on the basis of MRI. According to the postnatal diagnosis, mild and severe microtia were confirmed in 43 and 49 ears, respectively. Among the 29 fetuses with a gestational age > 28 weeks, 23 ears were suspected to have EAC atresia according to MRI and 21 ears were ultimately confirmed to have EAC atresia. The accuracy of MRI in diagnosing microtia and EAC atresia was 93.68% and 93.10%, respectively.

Conclusion

MRI shows good performance in diagnosing fetal microtia and has the potential to evaluate its severity on the basis of classification and EAC status.

Clinical relevance statement

This study was aimed at investigating the role of MRI in the diagnosis and classification of fetal microtia. MRI shows good performance and can help evaluate microtia severity and EAC atresia, thus allowing for better clinical management.

Key Points

• MRI is a useful adjunct to prenatal ultrasound.

• MRI has a higher accuracy rate than ultrasound in diagnosing fetal microtia.

• The accurate classification of fetal microtia and the diagnosis of external auditory canal atresia through MRI may help guide clinical management.
PALAEOASSOCIA as a methodological tool for phytosociological analyses is further developed
Authors: Brinkkemper Otto , Schepers Mans , Van Tongeren Onno
Published: June 2023

The earlier version of PALAEOASSOCIA involved a considerable input of manual labour in sorting species tables with association data to identify plant communities that could have been present. A large archaeobotanical dataset from the site of Best (The Netherlands) was used to judge whether this manual sorting results in subjective results. As these were found, we developed a fully automatic version of PALAEOASSOCIA, including this sorting process. Likelihood clustering with prior probability yielded the highest number of associations recovered from four samples, and was therefore chosen as the optimal clustering method. The sorted tables are automatically converted to syntaxonomical groups. The hierarchical level of these groups can be pre-defined by the user of the program. Syntaxa that are highly improbable geographically cannot be ruled out a priori, but need to be removed manually. PALAEOASSOCIA is not meant to replace other methods of ecological interpretations of archaeobotanical data, but instead as a tool to obtain a more detailed result.
Long-term follow-up suggests high satisfaction rates for bulbomembranous radiation-induced urethral stenoses treated with anastomotic urethroplasty
Authors: Barnard John , Liaw Aron , Gelman Joel
Published: June 2023

Purpose

To analyze patients who underwent anastomotic urethroplasty for radiationinduced bulbomembranous urethral stricture/stenosis (RIS) due to prostate cancer treatment with up to 19 years of follow-up and assess long-term patient reported outcomes (PROMs). Long-term follow-up with the inclusion of urethroplasty specific PROMs is lacking in the available research.

Methods

Patients who underwent anastomotic urethroplasty for RIS were identified from 2002 to 2020. Inclusion criteria included completion of 4-month post-operative cystoscopy and PROMs including IPSS, SHIM, MSHQ-EF, 6Q-LUTS, and global satisfaction queries at 4 months. PROMs were assessed annually thereafter, and cystoscopy was performed for adverse change in PROMs or worsening uroflow/PVR parameters. PROMs were compared at pre-op, post-op, and most recent follow-up.

Results

23 patients met inclusion criteria. Short-term anatomic success was 95.7%. At a mean follow-up of 73.1 months (9.1–228.9), one late recurrence occurred for an overall success of 91.3%. Significant and sustained objective improvement was identified in voiding scores, quality of life, and urethroplasty specific PROMs. Satisfaction was 91.3% despite sexual side effects, and 95.7% of patients stated they would have surgery again knowing their outcome at a mean of over 6 years’ follow up.

Conclusions

RIS are challenging problems, but durable symptomatic relief is achievable in well-selected patients. Patients with bulbomembranous RIS should be appropriately counseled regarding the risk of urinary incontinence and sexual side effects after anastomotic urethroplasty. However, long-term success is high, and overall QoL will have sustained subjective improvement in most cases.
On the Omnipresence of Spurious Local Minima in Certain Neural Network Training Problems
Authors: Christof Constantin , Kowalczyk Julia
Published: June 2023

We study the loss landscape of training problems for deep artificial neural networks with a one-dimensional real output whose activation functions contain an affine segment and whose hidden layers have width at least two. It is shown that such problems possess a continuum of spurious (i.e., not globally optimal) local minima for all target functions that are not affine. In contrast to previous works, our analysis covers all sampling and parameterization regimes, general differentiable loss functions, arbitrary continuous nonpolynomial activation functions, and both the finite- and infinite-dimensional setting. It is further shown that the appearance of the spurious local minima in the considered training problems is a direct consequence of the universal approximation theorem and that the underlying mechanisms also cause, e.g., $$L^p$$

L
p

-best approximation problems to be ill-posed in the sense of Hadamard for all networks that do not have a dense image. The latter result also holds without the assumption of local affine linearity and without any conditions on the hidden layers.
Nonunion of the so-called acromion: a systematic review with consideration of the terminology
Authors: Ogawa Kiyohisa , Matsumura Noboru , Yoshida Atsushi , Inokuchi Wataru
Published: June 2023

Introduction

There is no widely accepted standard for the classification and treatment of traumatic acromion/scapular spine fracture nonunion due to the scarcity of this condition and the confusion of terminology.

Materials and methods

PubMed and Scopus were searched using “scapular fracture” and “acromion fracture” or “scapular spine fracture” as search terms. The inclusion criteria were English full-text articles concerning acromion/scapular spine fracture nonunion that described patient characteristics and presented appropriate images. The exclusion criteria were cases without appropriate images. Citation tracking was conducted to find additional articles and notable full-text articles written in other languages. Fractures were classified using our newly proposed classification system.

Results

Twenty-nine patients (19 men, 10 women) with 29 nonunions were identified. There were four type I, 15 type II, and 10 type III fracture nonunions. Only 11 fractures were isolated. The mean period from initial injury to final diagnosis was 35.2 ± 73.2 months (range 3–360 months) (n = 25). The most frequent cause of delayed diagnosis was conservative treatment for fracture in 11 patients, followed by oversight by the physician in 8. The most common reason for seeking medical advice was shoulder pain. Six patients received conservative therapy, and 23 received operative treatment. Fixation materials included various plates in 15 patients, and tension band wiring in 5. Bone grafting was performed in 16 patients (73%, 16/22). Of the 19 surgically treated patients with adequate follow-up, the outcome was rated excellent in 79%.

Conclusions

Isolated acromion/scapular spine fracture nonunion is rare. Fracture type II and III, arising in the anatomical scapular spine, accounted for 86% of the fractures. Computed tomography is required to prevent fracture oversight. Surgical therapy produces good stable results. However, it is important to select the appropriate surgical fixation method and material after considering the anatomical characteristics of the fracture and stress on the fractured portion.

Level of evidence

V
Much higher prevalence of keratoconus than announced results of the Gutenberg Health Study (GHS)
Authors: Marx-Gross Susanne , Fieß Achim , Münzel Thomas , Wild Philipp Sebastian , Beutel Manfred Elmar , Schmidtmann Irene , Lackner Karl Johannes , Pfeiffer Norbert , Schuster Alexander Karl-Georg
Published: June 2023

Keratoconus appears to be a rare corneal disease with a prevalence previously estimated at 1:2000. The aim of our study was to investigate the prevalence of keratoconus in a large German cohort and to evaluate possible associated factors.

Method

In the population-based, prospective, monocentric cohort study, Gutenberg Health Study, 12,423 subjects aged 40–80 years were examined at the 5-year follow-up. Subjects underwent a detailed medical history and a general and ophthalmologic examination including Scheimpflug imaging. Keratoconus diagnosis was performed in two steps: all subjects with conspicuous TKC analysis of corneal tomography were included in further grading.

Prevalence and 95% confidence intervals were calculated. Logistic regression analysis was carried out to investigate association with age, sex, BMI, thyroid hormone, smoking, diabetes, arterial hypertension, atopy, allergy, steroid use, sleep apnea, asthma, and depression.

Results

Of 10,419 subjects, 75 eyes of 51 subjects were classified as having keratoconus. The prevalence for keratoconus in the German cohort was 0.49% (1:204; 95% CI: 0.36–0.64%) and was approximately equally distributed across the age decades. No gender predisposition could be demonstrated.

Logistic regression showed no association between keratoconus and age, sex, BMI, thyroid hormone, smoking, diabetes, arterial hypertension, atopy, allergy, steroid use, sleep apnea, asthma, and depression in our sample.

Conclusion

The prevalence of keratoconus disease in a mainly Caucasian population is approximately tenfold higher than previously reported in the literature using latest technologies (Scheimpflug imaging). Contrary to previous assumptions, we did not find associations with sex, existing atopy, thyroid dysfunction, diabetes, smoking, and depression.
Refining vitrectomy for proliferative diabetic retinopathy
Authors: Chen San-Ni , Chen Shih-Jen , Wu Tsung-Tien , Wu Wei-Chi , Yang Chang-Hao , Yang Chung-May
Published: June 2023

Pars plana vitrectomy (PPV) is the main treatment modality for patients with severe diabetic retinopathy. With the development of systems for microincision, wide-angle viewing, digitally assisted visualization, and intraoperative optical coherence tomography, contemporary PPV for diabetic retinopathy has been performed on a wider range of indications than previously considered. In this article, we reviewed, in conjunction with our collective experiences with Asian patients, the applications of new technologies for PPV in eyes with diabetic retinopathy and highlighted several important procedures and entities not generally reiterated in the literature, in order for vitreoretinal surgeons to optimize their approaches when facing the challenges imposed by the complications in diabetic eyes.
Effect of ghrelin administration on postoperative inflammatory response and bodyweight loss in patients with oesophageal cancer undergoing oesophagectomy: a systematic review and meta-analysis
Authors: Forshaw Elizabeth , Hajibandeh Shahin , Hajibandeh Shahab
Published: June 2023

Objectives

To investigate the effect of postoperative ghrelin therapy on postoperative inflammatory response and bodyweight loss in patients undergoing an oesophagectomy for oesophageal cancer.

Methods

We conducted a systematic search using electronic information databases in accordance to PRISMA standards to identify studies comparing outcomes after oesophagectomy in patients who were and were not administered ghrelin in the postoperative period. Meta-analysis of the outcomes using random effects modelling was conducted. The Cochrane collaboration’s tool and ROBINS-I tool were used for risk of bias assessment of the included studies.

Results

Five studies including 192 patients were selected for analysis. Ghrelin therapy was associated with a significantly shorter duration of systemic inflammatory response syndrome (SIRS) (MD: − 2.72, P = 0.0001), lower CRP level on postoperative day 3 (MD: − 3.64, P < 0.0001), and less total bodyweight loss (MD: − 1.87, P = 0.14). There was no differences between the two groups in IL-6 level on postoperative day 3 (MD: − 19.65, P = 0.32), total lean body weight loss (MD: − 1.87, P = 0.14), total body fat loss (MD: 0.15, P = 0.84), pulmonary complications (OR: 0.47, P = 0.12), anastomotic leak (OR: 1.17, P = 0.78), wound complications (OR: 1.64, P = 0.63), postoperative bleeding (OR: 0.32, P = 0.33), arrhythmia (OR: 1.22, P = 0.77).

Conclusions

Administration of ghrelin following oesophagoectomy may reduce duration of postoperative SIRS and bodyweight loss. Whether shorter duration of SIRS and less bodyweight loss resulted from postoperative ghrelin therapy can translate into improved morbidity or mortality outcomes remains unknown. There is a need for randomised controlled trials with robust statistical power to investigate the role of postoperative ghrelin therapy on morbidity and mortality outcomes in patients undergoing oesophagectomy.
Population history modulates the fitness effects of Copy Number Variation in the Roma
Authors: Antinucci Marco , Comas David , Calafell Francesc
Published: June 2023

We provide the first whole genome Copy Number Variant (CNV) study addressing Roma, along with reference populations from South Asia, the Middle East and Europe. Using CNV calling software for short-read sequence data, we identified 3171 deletions and 489 duplications. Taking into account the known population history of the Roma, as inferred from whole genome nucleotide variation, we could discern how this history has shaped CNV variation. As expected, patterns of deletion variation, but not duplication, in the Roma followed those obtained from single nucleotide polymorphisms (SNPs). Reduced effective population size resulting in slightly relaxed natural selection may explain our observation of an increase in intronic (but not exonic) deletions within Loss of Function (LoF)-intolerant genes. Over-representation analysis for LoF-intolerant gene sets hosting intronic deletions highlights a substantial accumulation of shared biological processes in Roma, intriguingly related to signaling, nervous system and development features, which may be related to the known profile of private disease in the population. Finally, we show the link between deletions and known trait-related SNPs reported in the genome-wide association study (GWAS) catalog, which exhibited even frequency distributions among the studied populations. This suggests that, in general human populations, the strong association between deletions and SNPs associated to biomedical conditions and traits could be widespread across continental populations, reflecting a common background of potentially disease/trait-related CNVs.