bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct optimization of dose–volume histogram metrics in radiation therapy treatment planning
Authors: Zhang Tianfang , Bokrantz Rasmus , Olsson Jimmy 
Published: September 2020

Abstract
We present a method of directly optimizing on deviations in clinical goal values in radiation therapy treatment planning. Using a new mathematical framework in which metrics derived from the dose–volume histogram are regarded as functionals of an auxiliary random variable, we are able to obtain volume-at-dose and dose-at-volume as infinitely differentiable functions of the dose distribution with easily evaluable function values and gradients. Motivated by the connection to risk measures in finance, which is formalized in this framework, we also derive closed-form formulas for mean-tail-dose and demonstrate its capability of reducing extreme dose values in tail distributions. Numerical experiments performed on a prostate and a head-and-neck patient case show that the direct optimization of dose–volume histogram metrics produced marginally better results than or outperformed conventional planning objectives in terms of clinical goal fulfilment, control of low- and high-dose tails of target distributions and general plan quality defined by a pre-specified evaluation measure. The proposed framework eliminates the disconnect between optimization functions and evaluation metrics and may thus reduce the need for repetitive user interaction associated with conventional treatment planning. The method also has the potential of enhancing plan optimization in other settings such as multicriteria optimization and automated treatment planning.
Witnessing non-objectivity in the framework of strong quantum Darwinism
Authors: Le Thao P , Olaya-Castro Alexandra 
Published: September 2020

Abstract
Quantum Darwinism is a compelling theory that describes the quantum-to classical transition as the emergence of objectivity of quantum systems. Spectrum broadcast structure and strong quantum Darwinism are two extensions of this theory with emphasis on state structure and information respectively. The complete experimental verification of these three frameworks, however, requires quantum state tomography over both the system and accessible environments, thus limiting the feasibility and scalability of experimental tests. Here, we introduce a subspace-dependent objectivity operation and construct a witness that detects non-objectivity by comparing the dynamics of the system-environment state with and without the objectivity operation. We then propose a photonic experimental simulation that implements the witnessing scheme. Our work proposes a route to further experimental exploration of the quantum to classical transition.
Landscape and taxon age are associated with differing patterns of hybridization in twoEucalyptus(Myrtaceae) subgenera
Authors: Robins T P , Binks R M , Byrne M , Hopper S D 
Published: September 2020

AbstractBackground and AimsHybridization is an important evolutionary process that can have a significant impact on natural plant populations. Eucalyptus species are well known for weak reproductive barriers and extensive hybridization within subgenera, but there is little knowledge of whether patterns of hybridization differ among subgenera. Here, we examine eucalypts of Western Australia’s Stirling Range to investigate how patterns of hybridization are associated with landscape and taxon age between the two largest Eucalyptus subgenera: Eucalyptus and Symphyomyrtus. In doing so, we tested a hypothesis of OCBIL (old, climatically buffered, infertile landscape) theory that predicts reduced hybridization on older landscapes.MethodsSingle nucleotide polymorphism markers were applied to confirm the hybrid status, parentage and genetic structure of five suspected hybrid combinations for subg. Eucalyptus and three combinations for subg. Symphyomyrtus.Key ResultsEvidence of hybridization was found in all combinations, and parental taxa were identified for most combinations. The older parental taxa assessed within subg. Eucalyptus, which are widespread on old landscapes, were identified as well-defined genetic entities and all hybrids were exclusively F1 hybrids. In addition, many combinations showed evidence of clonality, suggesting that the large number of hybrids recorded from some combinations is the result of long-term clonal spread following a few hybridization events rather than frequent hybridization. In contrast, the species in subg. Symphyomyrtus, which typically occur on younger landscapes and are more recently evolved, showed less distinction among parental taxa, and where hybridization was detected, there were high levels of introgression.ConclusionsReduced hybridization in subg. Eucalyptus relative to extensive hybridization in subg. Symphyomyrtus affirmed the hypothesis of reduced hybridization on OCBILs and demonstrate that clade divergence times, landscape age and clonality are important drivers of differing patterns of speciation and hybridization in Eucalyptus.
Long-distance dispersal of the beach strawberry, Fragaria chiloensis, from North America to Chile and Hawaii
Authors: Hancock James F , Prince Harold H 
Published: September 2020

Abstract

Background and Aims
The beach strawberry, Fragaria chiloensis, is found in a narrow coastal band from the Aleutian Islands to central California and then jumps thousands of kilometres all the way to Hawaii and Chile. As it probably had a North American origin, it must have been introduced to the other locations by long-distance dispersal. The aim of this study was to determine which agent carried the beach strawberry to its Pacific and South American locations.

Methods
A deductive framework was constructed to separate between the possible modes of long-distance dispersal involving animals, wind and ocean currents. Bird migration was subsequently identified as the most likely scenario, and then the routes, habitats, feeding preferences and flight distances of all the shorebird species were evaluated to determine the most likely carrier.

Key Results
Six species migrate between North America and Chile and feed on the beaches and rocky shores where F. chiloensis grows naturally: Black-bellied Plovers, Greater Yellowlegs, Ruddy Turnstones, Sanderlings, Whimbrels and Willets. Of these, only two eat fruit and migrate in long continuous flight: Ruddy Turnstones and Whimbrels. Two species travel between North America and Hawaii, eat fruit and forage on the beaches and rocky shores where F. chiloensis grows naturally: Pacific Golden-plovers and Ruddy Turnstones. Ruddy Turnstones eat far less fruit than Pacific Golden-plovers and Whimbrels, making them less likely to have introduced the beach strawberry to either location.

Conclusions
We provide evidence that F. chiloesis seeds were probably dispersed to Hawaii by Pacific Golden-plovers and to Chile by Whimbrels.
A Simple and Rapid High-Performance Liquid Chromatography—Photodiode Array Method for Quantitation of Triacetin Contents From 30 Batches Produced in China
Authors: Li Ran , Pan Xi , Wang Hao , Guo Guoning , Huang Long , Wei Min , Ma Yuanren , Zhang Jinyan , Hao Ji , Song Xuyan , Yang Xinzhou 
Published: September 2020

Abstract
In our present study, the standard chemicals of triacetin were purified by reverse-phase and normal-phase semi-preparative high-performance liquid chromatography (HPLC), and 1H NMR and 13C NMR were employed to determine the purity and structure of triacetin. Moreover, a simple and rapid HPLC-photodiode array (PDA) method was developed to determine the contents of triacetin in 30 batches from different suppliers. The chromatographic separation was performed on a Phenomenex Gemini-NX C18 column (250 × 4.6 mm, 5 μm) using a gradient elution system of water and acetonitrile (contained 0.1% of formic acid) solution with a flow rate of 1.0 mL/min at 30°C at 210 nm. Sample preparation method is rapid and energy efficient, and the obtained sample have a good purity. Validation shows good specificity, linearity (R2 = 0.9995), precision, stability, repeatability (% RSD &lt; 2.80) and the average recovery (99.72%) of triacetin. The content of triacetin in most samples is concentrated in 94–97%. This developed approach is simple, rapid, accurate and can be used to quickly determine the purity and the content of triacetin in plasticizers and filter plugs.
Large non-coronary sinus of Valsalva aneurysm: a case report of an unusual cause of angina pectoris
Authors: Iwakawa Hidehiro , Iino Takako , Yamamoto Hiroshi , Watanabe Hiroyuki 
Published: September 2020

Abstract

Background
Sinus of Valsalva aneurysm (SVA) is a rare cardiac abnormality occurring in 0.09% of the general population, but few reports have examined its recurrence. Unruptured SVAs are usually asymptomatic.

Case summary
A 50-year-old woman presented with chest pain and a history of surgery for a ruptured right coronary SVA 32 years prior. Echocardiography showed the recurrence of an unruptured SVA of the non-coronary sinus with moderate aortic regurgitation, severe mitral regurgitation, and severe tricuspid regurgitation. Cardiac computed tomography (CT) revealed compression of the right coronary artery (RCA) between the SVA and sternum. Adenosine triphosphate stress myocardial perfusion imaging (MPI) identified reversible ischaemia of the inferior wall. The patient underwent patch closure of the SVA, aortic valve replacement, mitral valvuloplasty, and tricuspid annuloplasty. Post-operative MPI showed no residual ischaemia, and CT confirmed both successful repair of the SVA and intact RCA.

Discussion
This case provides two noteworthy findings. First, the SVA recurred after 32 years. Second, a non-coronary SVA causing myocardial ischaemia is extremely rare given the long anatomical distance between the non-coronary sinus and coronary arteries. In our patient, the non-coronary SVA grew large enough within the anterior mediastinum to cause RCA compression.
The Geography of Unconventional Innovation
Authors: Berkes Enrico , Gaetani Ruben 
Published: September 2020

Abstract
Using a newly assembled data set of US patents, we show that innovation activity is less concentrated in high-density locations than commonly believed. Yet, inventions based on atypical combinations of knowledge are indeed more prevalent in high-density urban centres. To interpret this relation, we propose that informal interactions in densely populated areas help knowledge flows between distant fields, but are less relevant for flows between close fields. We build a model of innovation in a spatial economy that endogenously generates the pattern observed in the data: specialised clusters emerge in low-density areas, whereas high-density locations diversify and produce unconventional ideas.
Breaking the silence of the grave: the agency of speech scrolls on late medieval French tombs
Authors: Marcoux Robert 
Published: September 2020

Abstract
Amongst the many visual stimuli that fill late medieval churches, text scrolls occupy an important place. Merging both image and text in the shape of written banderoles, they add a layer of ‘sound’ to a variety of objects. This article deals with their specific use on funeral monuments where, acting as ‘speech scrolls’, they provide the dead with a distinctive voice. The musical resonances of the texts that appear on such speech scrolls is explored, and special focus is given to their presence on cadaver tombs in order to explore the agency held by the uncanny image of talking corpses within the context of late medieval strategies for the afterlife.
Fuga and invertible counterpoint in Byrd’s Cantiones sacrae (1589): some preliminary observations
Authors: Grimshaw Julian 
Published: September 2020

Abstract
This article aims to shed light on aspects of Byrd’s contrapuntal technique—particularly in relation to the crafting of fuga (or imitation)—by subjecting to close analysis a small sample from his Cantiones sacrae (1589), and in so doing offers in effect a trailer for the study of the collection as a whole. A number of issues are raised which indicate some of the directions in which future research in this area might be taken. These include the extent to which material is, or appears to be, reused by Byrd within a motet or across different motets, or indeed whether it may be borrowed from another composer, although this is a subordinate consideration in relation to Byrd’s reuse of his own material. While passages may appear to resemble each other—because they use similar subjects—sometimes it is a superficial likeness only, and when one delves below the surface one finds that the fuga is constructed quite differently. Byrd’s use of fuga is often far from straightforward, and leads one to conjecture that at times there was likely to have been some kind of pre-compositional planning: duos with inbuilt cadence formulas arise, and at the same time complexes of triple (invertible) counterpoint are introduced that take the procedures to another level of intricacy.
Reclaiming a Transgender History: The Intertextual Life of Charlotte Charke
Authors: Jack Jesse 
Published: September 2020

Abstract
Feminist historians and eighteenth-century scholars alike have employed strategic essentialisms of identity categories like the sapphic to reclaim the historical presence and agency of social groups whose histories have been erased (or obscured) under patriarchy. Methodologically, strategic essentialisms enable the speculative alignment of eighteenth-century figures with contemporary identity categories even though such categories may not have been constituted as such at the time. Works like Susan Lanser’s Sexuality of History exemplify the use of strategic essentialisms to retain a phenomenological position in relation to power structures without assimilating historical figures into contemporary identity constructs.1 Though work like Lanser’s exists for lesbian and gay identities, similar work has yet to focus on the intertextual experience of transgender embodiment, despite the fact that scholars have recently argued that the lack of a speculative transgender/transsexual history in the West has led to the problematic interpolation of so-called ‘third genders’ across the globe through a Western (largely white) lens.2 In this article, I seek to construct and employ a strategic essentialism of Western trans embodiment and experience to reconstitute the historical presence and agency of individuals whose unique experiences align in degrees to transgender identity today.3 I argue that the intertextual experience of Charlotte Charke with her multi-faceted identities and roles, her resistance to pseudo-histories, as well as her negotiation and generation of origin narratives and embodied borderlands, constitutes a phenomenology of intertextuality and serves as a viable starting place for the (re)construction of a lost, Western transgender history.
Measuring More Than Exposure: Does Stress Appraisal Matter for Black–White Differences in Anxiety and Depressive Symptoms Among Older Adults?
Authors: Brown Lauren L , Abrams Leah R , Mitchell Uchechi A , Ailshire Jennifer A 
Published: September 2020

Abstract

Background and Objectives
Prior research and theory suggest that exposure to objectively stressful events contributes to mental health disparities. Yet, blacks report higher cumulative stress exposure than whites but lower levels of common psychiatric disorders. In order to understand why blacks bear disproportionate stress exposure but similar or better mental health relative to whites, we need to consider race differences in not only stress exposure, but also stress appraisal—how upsetting stress exposures are perceived to be.

Research Design and Methods
We examine whether race differences in the number of reported chronic stressors across 5 domains (health, financial, residential, relationship, and caregiving) and their appraised stressfulness explain black–white differences in anxiety and depressive symptoms. Data come from 6019 adults aged older than 52 from the 2006 Health and Retirement Study.

Results
Older blacks in this sample experience greater exposure to chronic stressors but appraise stressors as less upsetting relative to whites. In fully adjusted models, stress exposure is related to higher levels of anxiety and depressive symptoms, and perceiving stress as upsetting is associated with higher symptomology for whites and blacks. We also find that blacks report greater anxiety symptoms but fewer depressive symptoms with more stress exposure relative to whites. Stress appraisal partially explains race differences in the association between stress exposure and anxiety symptoms and fully explains race differences in the association between exposure and depressive symptoms.

Discussion and Implications
The relationship between race, chronic stress exposure, and mental health is mediated by stress appraisal. Stress appraisal provides insight on important pathways contributing to black–white mental health disparities in older adulthood.
The consequence of COVID-19: how the United States moved from security provider to security consumer
Authors: Reich Simon , Dombrowski Peter 
Published: September 2020

Abstract
Deliberations over the COVID-19 pandemic's long-term effects on the global balance of power have spurred a large and rancorous debate, including speculation about a shift in the definition of national security and prescriptions about where it should focus. That argument will no doubt continue. But we argue that one consequence is already evident: the United States has spent the last seventy years portraying itself as a security provider in all key domains—for many an intrinsic component of its status as a global leader. One reasonable broad conclusion from the US struggle with COVID-19 is that it has further forfeited its broad leadership position on the basis of its behaviour. Yet that, although possibly true, would only portray one element of the story. The more profound insight exposed by COVID-19 is of a new reality: in a world where both naturogenic and anthropogenic threats pose immense national security challenges, decades of mistaken assumptions and policy choices have created a new environment, one where the United States has been redefined as a security consumer, at least in terms of international public health issues associated with the spread of deadly infectious diseases.
Translocation of aberrant left subclavian artery and resection of Kommerell diverticulum during the concomitant repair of intracardiac anomalies
Authors: An Kang , Li Shoujun , Yan Jun , Wang Xu , Hua Zhongdong 
Published: September 2020

Abstract

OBJECTIVES
To assess the safety and efficacy of the translocation of the aberrant left subclavian artery (LSCA) and resection of the Kommerell diverticulum during the concomitant repair of intracardiac anomalies for paediatric patients who had a right-sided aortic arch.

METHODS
A retrospective review of paediatric patients who were diagnosed right-sided aortic arch, aberrant LSCA, Kommerell diverticulum and intracardiac anomalies between 2015 and 2019 was conducted. Patients who underwent translocation of the aberrant LSCA, diverticulum resection and concomitant intracardiac repair were included.

RESULTS
Eight patients underwent translocation of aberrant LSCA, diverticulum resection, ligamentum division and concomitant repair of the associated intracardiac anomalies. All patients were male. The median age was 1.3 years (range 0.4–5.5 years) and the median weight was 10.0 kg (range 6.1–21.0 kg). The most commonly combined intracardiac anomaly was a ventricular septal defect. Seven patients (87.5%) had preoperative respiratory or gastrointestinal symptoms. There was no early mortality and no postoperative complications. During the median follow-up of 23 months (range 4–43 months), no patient had residual respiratory or gastrointestinal symptoms. A postoperative computed tomography scan was performed in 3 patients, all of which showed patent LSCA–left carotid artery anastomosis.

CONCLUSIONS
Translocation of the aberrant LSCA and resection of the Kommerell diverticulum can be safely performed during the concomitant repair of intracardiac anomalies for paediatric patients. This approach could eliminate residual respiratory and gastrointestinal symptoms, and prevent reintervention in the future.
Case Series: A case of familial thymomatous myasthenia gravis in a family of three male brothers
Authors: Elseidy Sheref A , Alkader Ahmed Abd Allah Abd , Naserallah Haitham Hassan , Awad Ahmed Khaled 
Published: September 2020

AbstractMyasthenia gravis (MG) is an autoimmune disease that occurs as a consequence of anti-acetylcholine (Ach) antibodies specifically targeting postsynaptic Ach receptors (AchR). This leads to the evolution of the classic symptoms of the disease, which range from mild symptoms of diplopia, muscle fatigue with repetitive movement up to severe affection of the respiratory muscle. The disease can occur as an isolated finding or co-exist with a concomitant thymic tumor or hyperplasia. Careful diagnosis is crucial for the development of the management plan. Nearly 10–15% of MG cases coexist with a thymic pathology and in these cases, surgical resection leads to the resolution of symptoms. Although thymomatous MG occurrence is non-heritable, its polygenic nature accounts for its rare familial variant. In this case, we report a family of three brothers with familial thymomatous MG who underwent thymectomy and improved after thymic surgical resection. Myasthenia gravis can occur as an isolated finding or as an association of thymic pathology. Careful discrimination between the two should be made for the elaboration of a management plan. Familial variant thymomatous myasthenia gravis is exceedingly rare. A familial survey is crucial for its management.
Which feedback mechanisms dominate in the high-pressure environment of the central molecular zone?
Authors: Barnes Ashley T , Longmore Steven N , Dale James E , Krumholz Mark R , Kruijssen J M Diederik , Bigiel Frank 
Published: September 2020

ABSTRACT
Supernovae (SNe) dominate the energy and momentum budget of stellar feedback, but the efficiency with which they couple to the interstellar medium (ISM) depends strongly on how effectively early, pre-SN feedback clears dense gas from star-forming regions. There are observational constraints on the magnitudes and time-scales of early stellar feedback in low ISM pressure environments, yet no such constraints exist for more cosmologically typical high ISM pressure environments. In this paper, we determine the mechanisms dominating the expansion of H ii regions as a function of size-scale and evolutionary time within the high-pressure ($P/k_\mathrm{B}\, \sim \, 10^{7-8}$ K cm−3) environment in the inner 100 pc of the Milky Way. We calculate the thermal pressure from the warm ionized (PH ii; 104 K) gas, direct radiation pressure (Pdir), and dust processed radiation pressure (PIR). We find that (1) Pdir dominates the expansion on small scales and at early times (0.01–0.1 pc; &lt;0.1 Myr); (2) the expansion is driven by PH ii on large scales at later evolutionary stages (&gt;0.1 pc; &gt;1 Myr); (3) during the first ≲ 1 Myr of growth, but not thereafter, either PIR or stellar wind pressure likely make a comparable contribution. Despite the high confining pressure of the environment, natal star-forming gas is efficiently cleared to radii of several pc within ∼ 2 Myr, i.e. before the first SNe explode. This ‘pre-processing’ means that subsequent SNe will explode into low density gas, so their energy and momentum will efficiently couple to the ISM. We find the H ii regions expand to a radius of ∼ 3 pc, at which point they have internal pressures equal with the surrounding external pressure. A comparison with H ii regions in lower pressure environments shows that the maximum size of all H ii regions is set by pressure equilibrium with the ambient ISM.