bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultra-broadband all-OPCPA petawatt facility fully based on LBO
Authors: Galletti Mario , Oliveira Pedro , Galimberti Marco , Ahmad Munadi , Archipovaite Giedre , Booth Nicola , Dilworth Emerald , Frackiewicz Andy , Winstone Trevor , Musgrave Ian , Hernandez-Gomez Cristina
Published: October 2020

A petawatt facility fully based on noncollinear optical parametric chirped pulse amplification (NOPCPA) technology, Vulcan OPPEL (Vulcan OPCPA PEtawatt Laser), is presented. This system will be coupled with the existing hybrid-CPA/OPCPA VULCAN laser system (500 J, 500 fs beamline; 250 J, ns regime beamline) based on Nd:glass amplification. Its pulse duration (20 times shorter) combined with the system design will allow the auxiliary beamline and its secondary sources to be used as probe beams for longer pulses and their interactions with targets. The newly designed system will be mainly dedicated to electron beam generation, but could also be used to perform a variety of particle acceleration and optical radiation detection experimental campaigns. In this communication, we present the entire beamline design discussing the technology choices and the design supported by extensive simulations for each system section. Finally, we present experimental results and details of our commissioned NOPCPA picosecond front end, delivering 1.5 mJ, ~180 nm (1/e2) of bandwidth compressed to sub-15 fs.
INTRINSIC SMALLNESS
Authors: MILLER JUSTIN
Published: October 2020

Recent work in computability theory has focused on various notions of asymptotic computability, which capture the idea of a set being “almost computable.” One potentially upsetting result is that all four notions of asymptotic computability admit “almost computable” sets in every Turing degree via coding tricks, contradicting the notion that “almost computable” sets should be computationally close to the computable sets. In response, Astor introduced the notion of intrinsic density: a set has defined intrinsic density if its image under any computable permutation has the same asymptotic density. Furthermore, introduced various notions of intrinsic computation in which the standard coding tricks cannot be used to embed intrinsically computable sets in every Turing degree. Our goal is to study the sets which are intrinsically small, i.e. those that have intrinsic density zero. We begin by studying which computable functions preserve intrinsic smallness. We also show that intrinsic smallness and hyperimmunity are computationally independent notions of smallness, i.e. any hyperimmune degree contains a Turing-equivalent hyperimmune set which is “as large as possible” and therefore not intrinsically small. Our discussion concludes by relativizing the notion of intrinsic smallness and discussing intrinsic computability as it relates to our study of intrinsic smallness.
CATEGORICAL SEMANTICS OF METRIC SPACES AND CONTINUOUS LOGIC
Authors: CHO SIMON
Published: October 2020

Using the category of metric spaces as a template, we develop a metric analogue of the categorical semantics of classical/intuitionistic logic, and show that the natural notion of predicate in this “continuous semantics” is equivalent to the a priori separate notion of predicate in continuous logic, a logic which is independently well-studied by model theorists and which finds various applications. We show this equivalence by exhibiting the real interval
$[0,1]$
in the category of metric spaces as a “continuous subobject classifier” giving a correspondence not only between the two notions of predicate, but also between the natural notion of quantification in the continuous semantics and the existing notion of quantification in continuous logic.

Along the way, we formulate what it means for a given category to behave like the category of metric spaces, and afterwards show that any such category supports the aforementioned continuous semantics. As an application, we show that categories of presheaves of metric spaces are examples of such, and in fact even possess continuous subobject classifiers.
CONGRUENCES MODULO 4 FOR WEIGHT ETA-PRODUCTS
Authors: CHEN RONG , GARVAN F. G.
Published: October 2020

We find and prove a class of congruences modulo 4 for eta-products associated with certain ternary quadratic forms. This study was inspired by similar conjectured congruences modulo 4 for certain mock theta functions.
Prosody and ideologies of embodiment: Variation in the use of pitch and articulation rate among fitness instructors
Authors: Esposito Lewis , Gratton Chantal
Published: October 2020

This article discusses semiotic connections among linguistic prosody, the body, and forms of physical activity. A quantitative study of the instructional styles of bodybuilding and yoga instructors on YouTube shows that bodybuilding instructors employ faster articulation rates and higher pitch (F0) than yoga instructors. We argue that articulation rate and pitch become semiotically linked to notions of energy, and the differences in the instructors’ styles are rooted in differences in levels of embodied energy that bodybuilding and yoga are assumed to require. Instructors employ linguistic features that reflect these ideologies of their activities, and in doing so, present themselves as embodied instantiations of their respective practices. This study shows that ideologies of the body as a physically active doer of things provide an important source for the generation of iconic, energy-related meanings. Crucially, we show that ideological notions of energy and embodied iconicity can drive group-level patterns of linguistic variation. (Prosody, iconicity, style, embodiment, social meaning, ideology)*
TIMING E SVILUPPO DEI SERVIZI SOCIALI IN EUROPA
Authors: Fargion Valeria
Published: October 2020

Introduzione

La letteratura sulwelfare stateha largamente privilegiato il settore pensionistico e la sanità, che peraltro costituiscono le componenti più rilevanti della spesa sociale in tutti i paesi europei. Tuttavia, nell'arco dell'ultimo decennio si è manifestato in ambito accademico un crescente interesse per le politiche socio-assistenziali. La nuova attenzione nei confronti di quest'area dipolicy, tradizionalmente considerata del tutto marginale nel contesto dei sistemi di protezione sociale, riflette la consapevolezza che nuovi bisogni sociali vanno diffondendosi in tutta Europa. A monte dei nuovi bisogni vi sono indubbiamente i profondi cambiamenti che hanno investito le nostre società sia sotto il profilo demografico sia per quanto riguarda la struttura familiare. Tali cambiamenti stanno infatti imponendo la ricerca di nuove soluzioni per far fronte alle esigenze di cura dei soggetti che non sono in grado di provvedere autonomamente a se stessi; ciò riguarda in primo luogo la terza e la quarta età, ma anche la prima infanzia, i portatori di handicap, i malati mentali ed i malati cronici.
Power, Personhood and Changing Emotional Engagement with Children's Burial during the Egyptian Predynastic
Authors: Barba Pablo
Published: October 2020

Archaeological analyses of child funerary remains have often revolved around discussions of ascribed status and demographic trends. Other social and spatial dimensions of child burial are often left unexplored. This article introduces a novel perspective, through the analysis of child burials in Predynastic Egypt. My analysis focuses on the changing rates and spatial distribution of child burials in community necropoleis, with special attention to how their placement was used to renegotiate power relationships, and perhaps even concepts of personhood, in Predynastic society. The importance of children's funerals for creating of a sense of community through attachment to place is also considered. Criticizing analyses that rely on quantitative data to the exclusion of other factors, I emphasize the contribution of childhood, practice theory, emotions and personhood for the study of social complexity. My arguments point towards significant changes in the emotional dimension of children's funerary practices experienced during the later fourth millenniumbc, and links these transformations to processes of state formation in Egypt.
Oviductal high concentration of K+suppresses hyperpolarization but does not prevent hyperactivation, acrosome reaction andin vitrofertilization in hamsters
Authors: Takei Gen L. , Kon Hiroe
Published: October 2020

Mammalian sperm have to undergo capacitation to be fertilization competent. Capacitated spermin vitroshow hyperpolarization of the membrane potential. It has been reported that in mouse membrane hyperpolarization is necessary for the acrosome reaction. We recently found that the fluid of the hamster oviduct, where fertilization occurs, contained a high potassium (K+) concentration (~20 mEq/l). This high K+concentration could depolarize the membrane potential and prevent the acrosome reaction/fertilization. Conversely, some beneficial effects on capacitation of high K+concentration or a high K/Na ratio were also reported. In the present study, we investigated the effects of oviduct high K+concentration on hamster sperm capacitation-associated events and fertilization. The present study confirmed that, in hamster sperm, membrane potential was hyperpolarized uponin vitrocapacitation, indicating that capacitation-associated hyperpolarization is a universal phenomenon among mammalian species. An increase in KCl concentration in the medium to 20 mM significantly depolarized the membrane potential and suppressed hyperpolarization when in the presence of >101 mM NaCl. However, an increase in the KCl concentration to 20 mM did not significantly affect the percentage of motile sperm, hyperactivation or the acrosome reaction. No effect of 20 mM KCl onin vitrofertilization was observed. In addition, no correlative changes in hyperactivation and the acrosome reaction with K/Na ratio were observed. These results suggested that in hamsters the oviduct K+concentration suppressed hyperpolarization but had no effect on capacitation andin vitrofertilization. Our results raised a question over the physiological significance of capacitation-associated hyperpolarization.
Sealed and revealed: Roman grave-opening practices
Authors: Brent Liana
Published: October 2020

In 1889, R. Lanciani witnessed the opening of the marble sarcophagus of Crepereia Tryphaena near the Mausoleum of Hadrian. He described the event as follows:

As a rule, the ceremony of cutting the brass clamps which fasten the lids of urns and sarcophagi is performed in one of our archaeological repositories, where the contents can be quietly and carefully examined, away from an excited and sometimes dangerous crowd. In the present case, this plan was found impracticable, because the coffin was ascertained to be filled with water which had, in the course of centuries, filtered in, drop by drop, through the interstices of the lid. […] No sooner had the seals been broken, and the lid put aside, than my assistants, myself, and the whole crowd of workmen from the Halls of Justice, were almost horrified at the sight before us.1
Not your classic bath: adopting and adapting Roman bathing habits in NW Gaul
Authors: Maréchal Sadi
Published: October 2020

Roman-style bathhouses are often used as markers to study processes of ‘Romanisation’, or, more generally, the spread of a Roman way of life throughout newly conquered regions. The building type, with its characteristic hypocaust system and pools, was a foreign element in regions unacquainted with communal bathing. However, to assume that these buildings were introduced and spread as a ‘package’, with the standard sequence of rooms and accompanying technology, would be oversimplifying a complex phenomenon of acceptance, rejection and adaptation. Since Roman baths are too often perceived as a mainly urban phenomenon, regions on the fringes of the empire with low levels of urbanisation, including the northern provinces, have been excluded from most seminal works.1 The present paper aims to examine a corpus of baths in NW Gaul from between the 1st and early 4th c. (i.e., the period between the first villa constructions and their abandonment following Germanic invasions) in order to challenge idées fixes2 that their plans were rigid and standardised and that most were in urban settings.
Reconstructing the phases of the fortifications of the legionary fortress at Novae (Moesia Inferior)
Authors: Zakrzewski Piotr
Published: October 2020

Since 1960, archaeological research in the area of the legionary base at Novae (fig. 1) has yielded many traces of its defensive system.1 Although the results were published regularly in field reports,2 information on the fortifications remained inadequate due to the methodologies and measuring equipment used in those days. Even with the new discoveries made in the 1980s and 1990s, most notably the earth-and-timber defences, many crucial issues including the chronology and construction sequence remained unresolved.3 Therefore in 2005 a review of the early excavations began within the framework of a postexcavation project, “Per lineam munitionum”. It involved recording all visible architectural and archaeological remains from previous seasons of fieldwork through the cleaning and deepening of old trenches. If the original stratigraphy was found to be too disturbed, soundings were extended. Advanced methods such as geodesy, photogrammetry and 3D modelling significantly improved the interpretation. In several years of topographic survey almost all of the early trenches were located, the general plan updated and corrected,4 and a detailed digital terrain model (DTM) produced (fig. 2).
Marketing and the Vulnerable
Authors: Brenkert George G.
Published: October 2020

Contemporary marketing is commonly characterized by the marketing concept which enjoins marketers to determine the wants and needs of customers and then to try to satisfy them. This view is standardly developed, not surprisingly, in terms of normal or ordinary consumers. Much less frequently is attention given to the vulnerable customers whom marketers also (and increasingly) target. Though marketing to normal consumers raises many moral questions, marketing to the vulnerable also raises many moral questions which are deserving of greater attention.

This paper has three objectives. First, it explores the notion of vulnerability which a target audience might (or might not) have. I argue that we must distinguish those who are specially vulnerable from normal individuals, as well as the susceptible and the disadvantaged - two other groups often distinguished in marketing literature. Second, I contend that marketing to the specially vulnerable requires that marketing campaigns be designed to ensure that these individuals are not treated unfairly, and thus possibly harmed. Third, I maintain that marketing programs which violate this preceding injunction are unethical or unscrupulous whether or not those targeted are harmed in some further manner. Accordingly, social control over marketing to the vulnerable cannot simply look to consumer injury as the measure of unfair treatment of the vulnerable.
A Kantian Theory of Capitalism
Authors: Bowie Norman E.
Published: October 2020

Some years ago Ed Freeman and William Evan wrote an article offering a Kantian stakeholder theory of corporate responsibility. Ed was kind enough to allow Tom Beauchamp and me to publish that previously unpublished piece in the second edition ofEthical Theory and Business. That article has appeared in every subsequent edition. But a Kantian theory of stakeholder relationships is not, I believe, a complete Kantian theory of the modem corporation. I believe Ed originally intended to expand that paper into a larger project but Ed’s philosophical interest in pragmatism has distanced him from Kantianism and his writings in stakeholder theory have gone in a different direction. Indeed in this postmodem feminist anti-foundationalist age, Kant is very much out of fashion. Since I am always out of fashion I had no trouble promising Ed I would complete the Kantian piece of the project. This essay is the condensed version and a partial fulfillment of my promise. A Kantian always keeps his promises.
Imagination, Fantasy, Wishful Thinking and Truth: Life is translation and we are all lost in it. (Clifford Geertz)
Authors: Ciulla Joanne B.
Published: October 2020

In “Moral Imagination and the Search for Ethical Decision-Making,” Patricia H. Werhane observes that people and institutions sometimes do unethical things because they have a narrow perspective on their situation and little in the way of moral imagination. She defines moral imagination as “an ability to imaginatively discern various possibilities for acting in a given situation and to envision the potential help and harm that are likely to result from a given action.” Werhane’s paper focuses on how the conceptual schemes of people and organizations hinder the exercise of moral imagination. She develops two key concepts for understanding moral imagination, memory or moral amnesia and empathy. Both of these give us a better picture of how imagination bridges the gap between moral principles and actions.
Lessons from the Wreck of the Exxon Valdez: The Need for Imagination, Empathy, and Courage
Authors: Hosmer Larue T.
Published: October 2020

Investigations of large scale industrial accidents generally take one of two alternative approaches to identifying the cause or causes of those destructive events. The first is legal analysis, which focuses on the mechanical failure or human error that immediately preceded the accident. The second is socio-technical reasoning, which centers on the complexities of the interlocking technological and organizational systems that brought about the accident. Both are retrospective, and provide little insight into the means of avoiding industrial accidents in the future. This article looks at six levels of managerial responsibility within a firm, and suggests specific changes at all levels that should logically help in the prevention or mitigation of these high impact/low probability events. The most basic need, however, is for imagination, empathy, and courage at the most senior level of the firm.
Moral Imagination in Organizational Problem-Solving: An Institutional Perspective
Authors: Vidaver-Cohen Deborah
Published: October 2020

This essay responds to Patricia Werhane’s 1994 Ruffin Lecture address, “Moral Imagination and the Search for Ethical Decision-making in Management,” using institutional theory as an analytical framework to explore conditions that either inhibit or promote moral imagination in organizational problem-solving. Implications of the analysis for managing organizational change and for business ethics theory development are proposed.
Auroral Image Classification With Deep Neural Networks
Authors: Kvammen Andreas , Wickstrøm Kristoffer , McKay Derek , Partamies Noora
Published: October 2020

Results from a study of automatic aurora classification using machine learning techniques are presented. The aurora is the manifestation of physical phenomena in the ionosphere‐magnetosphere environment. Automatic classification of millions of auroral images from the Arctic and Antarctic is therefore an attractive tool for developing auroral statistics and for supporting scientists to study auroral images in an objective, organized, and repeatable manner. Although previous studies have presented tools for detecting aurora, there has been a lack of tools for classifying aurora into subclasses with a high precision (>90%). This work considers seven auroral subclasses: breakup, colored, arcs, discrete, patchy, edge, and faint. Six different deep neural network architectures have been tested along with the well‐known classification algorithms: k‐nearest neighbor (KNN) and a support vector machine (SVM). A set of clean nighttime color auroral images, without clearly ambiguous auroral forms, moonlight, twilight, clouds, and so forth, were used for training and testing the classifiers. The deep neural networks generally outperformed the KNN and SVM methods, and the ResNet‐50 architecture achieved the highest performance with an average classification precision of 92%.
Theoretical Models for the Effective Electrical Conductivity of Transversely Isotropic Rocks With Inclined Penny‐Shaped Cracks
Authors: Yan Han , Han Tongcheng , Fu Li‐Yun
Published: October 2020

The existence of cracks can significantly influence the electrical properties of rocks, and electrical exploration has been applied for the detection and characterization of cracks. However, the premise is the knowledge of the quantitative effects of cracks on the electrical properties of fractured rocks, and theoretical models have provided means to obtain such knowledge. In this work, we derive explicit theoretical models for the anisotropic electrical conductivity of transversely isotropic (TI) rocks with inclined and rotated cracks, as well as cracks with random orientation distribution. Based on the developed models, we study systematically and quantitatively the effects of the crack properties and distributions on the anisotropic electrical conductivity of cracked rocks. We show that for TI rocks with aligned cracks, the inclination angle of the cracks affects both the vertical and the horizontal electrical conductivities, whereas the rotation angle only influences the horizontal electrical conductivity, although both the two angles can lead to the global rotations of the principal axes of the electrical conductivity tensor. On the other hand, the conductivity of TI rocks containing randomly distributed cracks remains transversely isotropic. For both aligned and randomly distributed cracks, the increasing crack volume fraction can linearly increase the electrical conductivity of the effective rocks, and cracks with lower aspect ratio show more significant effects on the electrical conductivity. The knowledge of the effects of the cracks on the TI rocks obtained in this study can be applied for more accurate interpretation of the electrical exploration data to better characterize cracked formations.
Joint Local and Teleseismic Tomography in the Central United States: Exploring the Mantle Below the Upper Mississippi Embayment and the Illinois Basin
Authors: Geng Y. , Powell C. A. , Saxena A.
Published: October 2020

Three‐dimensional, high‐resolution crustal and upper mantle P and S wave velocity (Vp and Vs) models are presented for the central United States using body wave tomography. The study utilizes local and teleseismic data recorded by the Northern Embayment Lithospheric Experiment stations, the CERI New Madrid Seismic Network, the Earthscope Transportable Array, and the Ozark Illinois INdiana Kentucky Flexible Array. Vp and Vs solutions are very similar and are well resolved in the depth range 40 to 400 km. Two anomalously slow regions are present below the Illinois Basin, forming a northwest dipping low‐velocity zone (LVZ) extending from ~200 to 400 km. Maximum anomaly magnitudes in the LVZ reach about −4% and −5% for Vp and Vs, respectively. The LVZ appears to connect to a well‐documented LVZ located below the northern Mississippi Embayment. The Illinois Basin velocity anomalies cannot be explained by elevated temperature alone and require compositional heterogeneity involving elevated orthopyroxene content in addition to an increase in iron and water content. The need for additional orthopyroxene suggests that the LVZ is being produced by metasomatism of mantle rocks by hydrous, silica‐rich fluids ascending from a slab fragment trapped in or near the transition zone. This supports previous interpretations for the existence of the LVZ below the Embayment. We suggest that the LVZs below the Mississippi Embayment and the Illinois Basin are linked to the presence of a large igneous province, which convection models suggest is currently located below the central United States.
Distinctive Signals in 1‐min Observations of Overshooting Tops and Lightning Activity in a Severe Supercell Thunderstorm
Authors: Borque Paloma , Vidal Luciano , Rugna Martín , Lang Timothy J. , Nicora María Gabriela , Nesbitt Stephen W.
Published: October 2020

This work examines a severe weather event that took place over central Argentina on 11 December 2018. The evolution of the storm from its initiation, rapid organization into a supercell, and eventual decay was analyzed with high‐temporal resolution observations. This work provides insight into the spatio‐temporal co‐evolution of storm kinematics (updraft area and lifespan), cloud‐top cooling rates, and lightning production that led to severe weather. The analyzed storm presented two convective periods with associated severe weather. An overall decrease in cloud‐top local minima IR brightness temperature (MinIR) and lightning jump (LJ) preceded both periods. LJs provided the highest lead time to the occurrence of severe weather, with the ground‐based lightning networks providing the maximum warning time of around 30 min. Lightning flash counts from the Geostationary Lightning Mapper (GLM) were underestimated when compared to detections from ground‐based lightning networks. Among the possible reasons for GLM's lower detection efficiency were an optically dense medium located above lightning sources and the occurrence of flashes smaller than GLM's footprint. The minimum MinIR provided the shorter warning time to severe weather occurrence. However, the secondary minima in MinIR that preceded the absolute minima improved this warning time by more than 10 min. Trends in MinIR for time scales shorter than 6 min revealed shorter cycles of fast cooling and warming, which provided information about the lifecycle of updrafts within the storm. The advantages of using observations with high‐temporal resolution to analyze the evolution and intensity of convective storms are discussed.
A Climatology of the Marine Atmospheric Boundary Layer Over the Southern Ocean From Four Field Campaigns During 2016–2018
Authors: Truong S. C. H. , Huang Y. , Lang F. , Messmer M. , Simmonds I. , Siems S. T. , Manton M. J.
Published: October 2020

A climatology of the marine atmospheric boundary layer (MABL) and the lower free troposphere over the Southern Ocean (SO) is constructed using 2,186 high‐resolution atmospheric soundings from four recent campaigns conducted in the period of 2016–2018. Relationships between the synoptic meteorology and MABL thermodynamic structure are examined using a k‐means cluster analysis, complemented by front and cyclone composite analyses. Seven distinct clusters are identified, five of which are consistent with an established climatology over the SO storm track. Two new clusters (C1 and C2) are introduced over the high‐latitude SO. C1 is commonly located poleward of the ocean polar front near mesocyclones, while C2 is located along the Antarctic coastline. A multilayer cloud structure is frequently present in clusters in the vicinity of fronts and cyclones, while a single‐layer coverage is more common in a suppressed environment, particularly at lower latitudes. A cloud‐free, multilevel inversion is frequently observed in cluster C2, possibly linked to the descending, dry, katabatic winds off the Antarctic coast. A strong, primary inversion is typically present in clusters at lower latitudes with high mean sea level pressure. Across the SO storm track and higher latitudes (cluster C1), a multilevel inversion structure is also commonly observed. A preliminary analysis of two case studies suggests that upper level advection and detrainment of convection associated with mesocyclones are potential drivers of the multilayer cloud coverage over the high‐latitude SO rather than the decoupling mechanisms common in the subtropics.
Gravity Wave Activity in the Atmosphere of Mars During the 2018 Global Dust Storm: Simulations With a High‐Resolution Model
Authors: Kuroda Takeshi , Medvedev Alexander S. , Yiğit Erdal
Published: October 2020

Gravity wave (GW) activity in the lower and middle atmosphere of Mars during the global dust storm of 2018 has been studied for the first time using a high‐resolution (GW‐resolving) general circulation model. Dust storm simulations were compared with those utilizing the climatological distribution of dust in the absence of storms. Both scenarios are based on observations of the dust optical depth by the Mars Climate Sounder instrument on board the Mars Reconnaissance Orbiter. The modeling reveals a reduction of the wave activity by a factor of 2 or more in the lower atmosphere, which qualitatively agrees with recent observations. It is associated with a decline of GW generation due to baroclinic and convective stabilization of the Martian troposphere induced by the increased amount of airborne aerosols during the storm. Contrary to the decrease of GW activity in the lower atmosphere, wave energy and momentum fluxes in the middle atmosphere increase by approximately the same factor. This enhancement of GW activity is caused by the changes in the large‐scale circulation, most importantly in the mean zonal wind, which facilitate vertical wave propagation by allowing for a greater portion of GW harmonics originated in the lower atmosphere to avoid filtering on their way to upper layers.
MEMS-actuated metasurface Alvarez lens
Authors: Han Zheyi , Colburn Shane , Majumdar Arka , Böhringer Karl F.
Published: October 2020

Miniature lenses with a tunable focus are essential components for many modern applications involving compact optical systems. While several tunable lenses have been reported with various tuning mechanisms, they often face challenges with respect to power consumption, tuning speed, fabrication cost, or production scalability. In this work, we have adapted the mechanism of an Alvarez lens – a varifocal composite lens in which lateral shifts of two optical elements with cubic phase surfaces give rise to a change in the optical power – to construct a miniature, microelectromechanical system (MEMS)-actuated metasurface Alvarez lens. Implementation based on an electrostatic MEMS generates fast and controllable actuation with low power consumption. The utilization of metasurfaces – ultrathin and subwavelength-patterned diffractive optics – as optical elements greatly reduces the device volume compared to systems using conventional freeform lenses. The entire MEMS Alvarez metalens is fully compatible with modern semiconductor fabrication technologies, granting it the potential to be mass-produced at a low unit cost. In the reported prototype operating at 1550 nm wavelength, a total uniaxial displacement of 6.3 µm was achieved in the Alvarez metalens with a direct-current (DC) voltage application up to 20 V, which modulated the focal position within a total tuning range of 68 µm, producing more than an order of magnitude change in the focal length and a 1460-diopter change in the optical power. The MEMS Alvarez metalens has a robust design that can potentially generate a much larger tuning range without substantially increasing the device volume or energy consumption, making it desirable for a wide range of imaging and display applications.
WAVE3 phosphorylation regulates the interplay between PI3K, TGF-β, and EGF signaling pathways in breast cancer
Authors: Wang Wei , Kansakar Urna , Markovic Vesna , Wang Bingcheng , Sossey-Alaoui Khalid
Published: October 2020

Both TGF-β and the PI3K-AKT signaling pathways are known activators of various intracellular pathways that regulate critical cellular functions, including cancer cell survival and proliferation. The interplay between these two oncogenic pathways plays a major role in promoting the initiation, growth, and progression of tumors, including breast cancers. The molecular underpinning of the inter-relationship between these pathways is, however, not fully understood, as is the role of WAVE3 phosphorylation in the regulation of tumor growth and progression. WAVE3 has been established as a major driver of the invasion–metastasis cascade in breast cancer and other tumors of epithelial origin. WAVE3 phosphorylation downstream of PI3K was also shown to regulate cell migration. Here we show that, in addition to PI3K, WAVE3 tyrosine phosphorylation can also be achieved downstream of TGF-β and EGF and that WAVE3 tyrosine phosphorylation is required for its oncogenic activity. Our in vitro analyses found loss of WAVE3 phosphorylation to significantly inhibit cell migration, as well as tumorsphere growth and invasion. In mouse models for breast cancer, loss of WAVE3 phosphorylation inhibited tumor growth of two aggressive breast cancer cell lines of triple-negative subtype. More importantly, we found that WAVE3 phosphorylation is also required for the activation of PI3K, TGF-β, and EGF signaling and their respective downstream effectors. Therefore, our study identified a novel function for WAVE3 in the regulation of breast cancer development and progression through the modulation of a positive feedback loop between WAVE3 and PI3K-TGF-β-EGF signaling pathways.
Visible-light-assisted multimechanism design for one-step engineering tough hydrogels in seconds
Authors: Wang Cong , Zhang Ping , Xiao Wenqing , Zhao Jiaqi , Shi Mengting , Wei Hongqiu , Deng Zhouhu , Guo Baolin , Zheng Zijian , Yu You
Published: October 2020

Tough hydrogels that are capable of efficient mechanical energy dissipation and withstanding large strains have potential applications in diverse areas. However, most reported fabrication strategies are performed in multiple steps with long-time UV irradiation or heating at high temperatures, limiting their biological and industrial applications. Hydrogels formed with a single pair of mechanisms are unstable in harsh conditions. Here we report a one-step, biocompatible, straightforward and general strategy to prepare tough soft hydrogels in a few tens of seconds under mild conditions. With a multimechanism design, the network structures remarkably improve the mechanical properties of hydrogels and maintain their high toughness in various environments. The broad compatibility of the proposed method with a spectrum of printing technologies makes it suitable for potential applications requiring high-resolution patterns/structures. This strategy opens horizons to inspire the design and application of high-performance hydrogels in fields of material chemistry, tissue engineering, and flexible electronics.
Crop switching reduces agricultural losses from climate change in the United States by half under RCP 8.5
Authors: Rising James , Devineni Naresh
Published: October 2020

A key strategy for agriculture to adapt to climate change is by switching crops and relocating crop production. We develop an approach to estimate the economic potential of crop reallocation using a Bayesian hierarchical model of yields. We apply the model to six crops in the United States, and show that it outperforms traditional empirical models under cross-validation. The fitted model parameters provide evidence of considerable existing climate adaptation across counties. If crop locations are held constant in the future, total agriculture profits for the six crops will drop by 31% for the temperature patterns of 2070 under RCP 8.5. When crop lands are reallocated to avoid yield decreases and take advantage of yield increases, half of these losses are avoided (16% loss), but 57% of counties are allocated crops different from those currently planted. Our results provide a framework for identifying crop adaptation opportunities, but suggest limits to their potential.
Unscrambling fluorophore blinking for comprehensive cluster detection via photoactivated localization microscopy
Authors: Platzer René , Rossboth Benedikt K. , Schneider Magdalena C. , Sevcsik Eva , Baumgart Florian , Stockinger Hannes , Schütz Gerhard J. , Huppa Johannes B. , Brameshuber Mario
Published: October 2020

Determining nanoscale protein distribution via Photoactivated Localization Microscopy (PALM) mandates precise knowledge of the applied fluorophore’s blinking properties to counteract overcounting artifacts that distort the resulting biomolecular distributions. Here, we present a readily applicable methodology to determine, optimize and quantitatively account for the blinking behavior of any PALM-compatible fluorophore. Using a custom-designed platform, we reveal complex blinking of two photoswitchable fluorescence proteins (PS-CFP2 and mEOS3.2) and two photoactivatable organic fluorophores (PA Janelia Fluor 549 and Abberior CAGE 635) with blinking cycles on time scales of several seconds. Incorporating such detailed information in our simulation-based analysis package allows for robust evaluation of molecular clustering based on individually recorded single molecule localization maps.
G3BP1 controls the senescence-associated secretome and its impact on cancer progression
Authors: Omer Amr , Barrera Monica Cruz , Moran Julian L. , Lian Xian J. , Di Marco Sergio , Beausejour Christian , Gallouzi Imed-Eddine
Published: October 2020

Cellular senescence is a known driver of carcinogenesis and age-related diseases, yet senescence is required for various physiological processes. However, the mechanisms and factors that control the negative effects of senescence while retaining its benefits are still elusive. Here, we show that the rasGAP SH3-binding protein 1 (G3BP1) is required for the activation of the senescent-associated secretory phenotype (SASP). During senescence, G3BP1 achieves this effect by promoting the association of the cyclic GMP-AMP synthase (cGAS) with cytosolic chromatin fragments. In turn, G3BP1, through cGAS, activates the NF-κB and STAT3 pathways, promoting SASP expression and secretion. G3BP1 depletion or pharmacological inhibition impairs the cGAS-pathway preventing the expression of SASP factors without affecting cell commitment to senescence. These SASPless senescent cells impair senescence-mediated growth of cancer cells in vitro and tumor growth in vivo. Our data reveal that G3BP1 is required for SASP expression and that SASP secretion is a primary mediator of senescence-associated tumor growth.
c-Myc inactivation of p53 through the pan-cancer lncRNA MILIP drives cancer pathogenesis
Authors: Feng Yu Chen , Liu Xiao Ying , Teng Liu , Ji Qiang , Wu Yongyan , Li Jin Ming , Gao Wei , Zhang Yuan Yuan , La Ting , Tabatabaee Hessam , Yan Xu Guang , Jamaluddin M. Fairuz B. , Zhang Didi , Guo Su Tang , Scott Rodney J. , Liu Tao , Thorne Rick F. , Zhang Xu Dong , Jin Lei
Published: October 2020

The functions of the proto-oncoprotein c-Myc and the tumor suppressor p53 in controlling cell survival and proliferation are inextricably linked as “Yin and Yang” partners in normal cells to maintain tissue homeostasis: c-Myc induces the expression of ARF tumor suppressor (p14ARF in human and p19ARF in mouse) that binds to and inhibits mouse double minute 2 homolog (MDM2) leading to p53 activation, whereas p53 suppresses c-Myc through a combination of mechanisms involving transcriptional inactivation and microRNA-mediated repression. Nonetheless, the regulatory interactions between c-Myc and p53 are not retained by cancer cells as is evident from the often-imbalanced expression of c-Myc over wildtype p53. Although p53 repression in cancer cells is frequently associated with the loss of ARF, we disclose here an alternate mechanism whereby c-Myc inactivates p53 through the actions of the c-Myc-Inducible Long noncoding RNA Inactivating P53 (MILIP). MILIP functions to promote p53 polyubiquitination and turnover by reducing p53 SUMOylation through suppressing tripartite-motif family-like 2 (TRIML2). MILIP upregulation is observed amongst diverse cancer types and is shown to support cell survival, division and tumourigenicity. Thus our results uncover an inhibitory axis targeting p53 through a pan-cancer expressed RNA accomplice that links c-Myc to suppression of p53.
Monitoring and modeling of lymphocytic leukemia cell bioenergetics reveals decreased ATP synthesis during cell division
Authors: Kang Joon Ho , Katsikis Georgios , Li Zhaoqi , Sapp Kiera M. , Stockslager Max A. , Lim Daniel , Vander Heiden Matthew G. , Yaffe Michael B. , Manalis Scott R. , Miettinen Teemu P.
Published: October 2020

The energetic demands of a cell are believed to increase during mitosis, but the rates of ATP synthesis and consumption during mitosis have not been quantified. Here, we monitor mitochondrial membrane potential of single lymphocytic leukemia cells and demonstrate that mitochondria hyperpolarize from the G2/M transition until the metaphase-anaphase transition. This hyperpolarization was dependent on cyclin-dependent kinase 1 (CDK1) activity. By using an electrical circuit model of mitochondria, we quantify mitochondrial ATP synthesis rates in mitosis from the single-cell time-dynamics of mitochondrial membrane potential. We find that mitochondrial ATP synthesis decreases by approximately 50% during early mitosis and increases back to G2 levels during cytokinesis. Consistently, ATP levels and ATP synthesis are lower in mitosis than in G2 in synchronized cell populations. Overall, our results provide insights into mitotic bioenergetics and suggest that cell division is not a highly energy demanding process.
Enhanced polymer mechanical degradation through mechanochemically unveiled lactonization
Authors: Lin Yangju , Kouznetsova Tatiana B. , Chang Chia-Chih , Craig Stephen L.
Published: October 2020

The mechanical degradation of polymers is typically limited to a single chain scission per triggering chain stretching event, and the loss of stress transfer that results from the scission limits the extent of degradation that can be achieved. Here, we report that the mechanically triggered ring-opening of a [4.2.0]bicyclooctene (BCOE) mechanophore sets up a delayed, force-free cascade lactonization that results in chain scission. Delayed chain scission allows many eventual scission events to be initiated within a single polymer chain. Ultrasonication of a 120 kDa BCOE copolymer mechanically remodels the polymer backbone, and subsequent lactonization slowly (~days) degrades the molecular weight to 4.4 kDa, > 10× smaller than control polymers in which lactonization is blocked. The force-coupled kinetics of ring-opening are probed by single molecule force spectroscopy, and mechanical degradation in the bulk is demonstrated. Delayed scission offers a strategy to enhanced mechanical degradation and programmed obsolescence in structural polymeric materials.
Design and clinical implementation of an open-source bionic leg
Authors: Azocar Alejandro F. , Mooney Luke M. , Duval Jean-François , Simon Ann M. , Hargrove Levi J. , Rouse Elliott J.
Published: October 2020

In individuals with lower-limb amputations, robotic prostheses can increase walking speed, and reduce energy use, the incidence of falls and the development of secondary complications. However, safe and reliable prosthetic-limb control strategies for robust ambulation in real-world settings remain out of reach, partly because control strategies have been tested with different robotic hardware in constrained laboratory settings. Here, we report the design and clinical implementation of an integrated robotic knee–ankle prosthesis that facilitates the real-world testing of its biomechanics and control strategies. The bionic leg is open source, it includes software for low-level control and for communication with control systems, and its hardware design is customizable, enabling reduction in its mass and cost, improvement in its ease of use and independent operation of the knee and ankle joints. We characterized the electromechanical and thermal performance of the bionic leg in benchtop testing, as well as its kinematics and kinetics in three individuals during walking on level ground, ramps and stairs. The open-source integrated-hardware solution and benchmark data that we provide should help with research and clinical testing of knee–ankle prostheses in real-world environments.
Mathematical modeling of the cardiovascular autonomic control in healthy subjects during a passive head-up tilt test
Authors: Ishbulatov Yurii M. , Karavaev Anatoly S. , Kiselev Anton R. , Simonyan Margarita A. , Prokhorov Mikhail D. , Ponomarenko Vladimir I. , Mironov Sergey A. , Gridnev Vladimir I. , Bezruchko Boris P. , Shvartz Vladimir A.
Published: October 2020

A mathematical model is proposed for the autonomic control of cardiovascular system, which takes into account two separated self-exciting sympathetic control loops of heart rate and peripheral vascular tone. The control loops are represented by self-exciting time-delay systems and their tone depends on activity of the aortic, carotid, and lower-body baroreceptors. The model is used to study the dynamics of the adaptive processes that manifest in a healthy cardiovascular system during the passive head-up tilt test. Computer simulation provides continuous observation of the dynamics of the indexes and variables that cannot be measured in the direct experiment, including the noradrenaline concentration in vessel wall and heart muscle, tone of the sympathetic and parasympathetic control, peripheral vascular resistance, and blood pressure. In the supine and upright positions, we estimated the spectral characteristics of the model variables, especially in the low-frequency band, and the original index of total percent of phase synchronization between the low-frequency oscillations in heart rate and blood pressure signals. The model demonstrates good quantitative agreement with the dynamics of the experimentally observed indexes of cardiovascular system that were averaged for 50 healthy subjects.
Task-based memory systems in contextual-cueing of visual search and explicit recognition
Authors: Geyer Thomas , Rostami Pardis , Sogerer Lisa , Schlagbauer Bernhard , Müller Hermann J.
Published: October 2020

Visual search is facilitated when observers encounter targets in repeated display arrangements. This ‘contextual-cueing’ (CC) effect is attributed to incidental learning of spatial distractor-target relations. Prior work has typically used only one recognition measure (administered after the search task) to establish whether CC is based on implicit or explicit memory of repeated displays, with the outcome depending on the diagnostic accuracy of the test. The present study compared two explicit memory tests to tackle this issue: yes/no recognition of a given search display as repeated versus generation of the quadrant in which the target (which was replaced by a distractor) had been located during the search task, thus closely matching the processes involved in performing the search. While repeated displays elicited a CC effect in the search task, both tests revealed above-chance knowledge of repeated displays, though explicit-memory accuracy and its correlation with contextual facilitation in the search task were more pronounced for the generation task. These findings argue in favor of a one-system, explicit-memory account of CC. Further, they demonstrate the superiority of the generation task for revealing the explicitness of CC, likely because both the search and the memory task involve overlapping processes (in line with ‘transfer-appropriate processing’).