bluuebunny/crossref_metadata_2025 huggingface dataset:
Helicopter Modelling
Authors: Ormiston Robert A.
Published: March 2023

I am pleased to have the honour of presenting the 18th Henson and Stringfellow Memorial Lecture. The subject of helicopter modelling is certainly appropriate because of the pioneering experiments that Henson and Stringfellow carried out with steam-powered plane models more than 50 years in advance of the Wright brothers. Although true powered flights were not quite achieved, these models were notable for excellence in overall design, the efficiency of their small steam engines, and their ultimate influence in later developments that culminated in the first successful aeroplane. Although not as well known, models were also extensively employed in the early development of the helicopter and have since become almost indispensable for advancing helicopter technology. The main emphasis of this lecture will be devoted to the diverse ways in which small-scale helicopter models are presently employed in advancing this technology. To best accomplish this objective, I have chosen specific examples of helicopter models to illustrate their versatility and wide range of application. The presentation of these models will also serve a secondary purpose—to demonstrate the advanced level of technology that now exists for producing these sophisticated and fascinating models.
An application of some aspects of optimal control
Authors: J. W. Hardy
Published: March 2023

In recent years considerable advances in the field of “optimal control” have been made. The impetus behind many of these advances has been derived from a growing demand that not only is it desirable, but also essential, that the design of a control system be optimised. This is particularly true of the aerospace industry in which the specification laid before the control systems designer usually demands the best possible performance for minimum cost (be that cost financial, on fuel, or on weight). Short of a major technological innovation, the problem becomes one of finding some means of meeting an ever increasing demand for performance, using existing technology. More attention has therefore been given in recent years to the study of optimal control, particularly since the advent of high speed, sophisticated scientific digital computers. Two of the major areas which have been explored have been the optimal design of systems, according to a quadratic performance criterion, and non-linear programming techniques. These are briefly discussed in Section 3 of this paper.
The Aerodynamics of Lifting Bodies at High Supersonic Speeds
Authors: Squire L. C.
Published: March 2023

A Euromech meeting on the aerodynamics of lifting bodies at high supersonic speeds was held at Churchill College, Cambridge on 30th and 31st July. Forty people attended from various European countries and 21 papers were presented. It is believed that these papers are fairly indicative of the range of current European work in this field. The present note gives a brief account of the work discussed at the meeting. A fuller report on the meeting is being prepared and will be circulated to all interested parties (copies may be obtained from the present author).
The Second International Symposium Concerning the Warsaw Convention
Authors: Roskill Justice
Published: March 2023

This half-day symposium was held at the Society on 4th November 1970. The proceedings were opened by the President, Air Commodore J. R. Morgan, OBE, FRAeS, who welcomed distinguished visitors from overseas and introduced the Chairman of the Symposium: Sir Eustace Roskill, a judge of the Queen's Bench Division and chairman of the commission to enquire into the siting of London's Third Airport.

Mr. A. W. G. Kean, principal Assistant Solicitor in the Department of Trade and Industry, was the first speaker; he outlined the background to current proposals for revision to the Warsaw Convention to be considered at a Diplomatic Conference in February 1971 in Guatemala.

Subsequent proceedings were divided into two main parts: Part I—in which European viewpoints were expressed; Part II—consisting of a selection of American viewpoints.

An important written contribution to the proceedings is a copy of official statistics gathered by the Civil Aeronautics Board for the purposes of the Diplomatic Conference and released to the Society by the US State Department which will be published, together with the Part II discussion, and the written contributions, in the March issue of the Journal.
Modification Techniques in the Matrix Force Method
Authors: Miller P. R. , Sarin R. K.
Published: March 2023

The problem of cut-outs in structures being analysed by the matrix force method is solved by Goodey by the method of undetermined multipliers. It can be shown that the final results are identical to those of ref. 2. In this note we demonstrate that the method of undetermined multipliers can also be used to incorporate modifications into a structure. This, in itself, is only of academic interest for a simple problem. However, it does give many advantages when dealing with more complex situations. The basic equations can be written down quite simply and the development of the subsequent matrix algebra follows the straightforward pattern for solving simultaneous equations. Also, where previous results can be used, this becomes apparent.
Some Studies on Skew Plates
Authors: Sundara Raja Iyengar K. T. , Srinivasan R. S. , Sundara Rajan C.
Published: March 2023

In their earlier paper the first two authors have given a solution to the problem of bending of clamped skew plates. The solution was obtained using the eigenfunctions of a beam. They have shown in their discussion that their results agree with other investigators except Kennedy who has used Galerkin's method. It was surprising to note that though both the authors’ and Kennedy's methods converged well, the results did not agree for all the cases and the difference being maximum for the rhombic case. It was mentioned in the discussion that additional work was desirable to resolve the difference. Hence in this note results using a different approach have been presented both for clamped and simply supported isotropic skew plates subjected to uniformly distributed load and the results are compared with the available ones.
Is There a Future for Europe in Aerospace?
Authors: Hotz Robert B.
Published: March 2023

It is indeed an honour and a pleasure to join with you in honouring the memory of one of the great pioneers in British aviation. When I read the story of Captain Frank Barnwell's life so ably presented by Major Bulman in the first of these lectures, I was struck by the indomitable spirit of a man who, at the age of 57, was still determined to flight test his own new design. It is the same type of spirit that sustained Alan Shepard through a decade of physical adversity to reach the moon at the age of 47 and perform on its surface with all of the vigour this mission required. It is this type of human spirit that has made all of the fabulous technical achievements possible, and it is this type of spirit that is an essential ingredient for the continued assault on the great unknowns that lie in murky darkness all along the frontiers of man's knowledge of himself and his universe.
Some Measured and Calculated Effects of Runway Unevenness on a Supersonic Transport Aircraft
Authors: Mitchell C. G. B.
Published: March 2023

Theoretical studies of the response of supersonic transport aircraft (SST) taxying and taking-off on uneven runways showed several years ago that the vertical acceleration in the cockpit of an SST of typical configuration would be greater than that in a subsonic transport on the same runway. The vibration would occur mainly at the frequency of bending of the fuselage, which might be 2 Hz, and would be forced by long, shallow undulations of the runway. These might have wavelengths of 50 ft to 300 ft (15 m to 90 m) and amplitudes of 1½ in to 4 in (0·04 m to 0·10 m) peak-to-peak, and are so unlike the usual concept of a rough surface that a different term, unevenness, is used to describe them.
The Economics of Airport Operation as affected by Transport Aircraft Design Trends
Authors: Read R. A.
Published: March 2023

It is of some historical significance that, after 25 years or so, a body still primarily associated with the aeronautical construction industry, is sufficiently concerned with the economics of airport operation, as affected by transport aircraft design trends, to invite a paper of this sort. Naturally enough, design trends of aircraft and their effect on economics have concerned airport authorities to a lesser or greater degree for a large part of that 25 years but from their remote position those responsible for airport design and operation have seldom been able to exert any real pressures upon aircraft designers. In addition, the old idea of airports as providing a form of subsidised social service, not required to be viable, also led to a fatalistic acceptance by airport operators, at least in the UK, of the vagaries of aircraft designers in expressing their individual talents and idiosyncrasies in widely differing design criteria. However, this era is now past and many airlines are becoming aware that wide changes of aircraft design criteria can lead to considerable extra cost in areas unconnected with the pure aircraft engineering and operational environment.
Facilities Planning for International Air Cargo
Authors: Leslie John C.
Published: March 2023

In 1970, at John F. Kennedy International Airport, New York, the value of international air cargo in and out is estimated at 5·9 thousand million dollars. That is about $16M on the average day. As in recent years, this will make JFK the number one customs port (sea or air) in the USA in terms of value of international cargo handled.

In 1969 at JFK some 409 000 short tons of international air cargo moved in and out, an average of 1263 tons or 2·5 million pounds per day. Using very rough conversion factors, this would fit into something like 500 containers 8 ft. by 8 ft. by 10 ft. This, of course, it not a real life illustration. Cargo comes in an infinite variety of shapes, sizes and weights—from massive machinery to fragile ladies’ garments on racks, from perishables to valuables.
Guided Weapon Design to Meet Cost Requirements
Authors: King G. E.
Published: March 2023

During the conceptual phases of a project the operational planning groups in government and industry carry out cost effectiveness analyses, using the techniques described by Mr. Kerr, to chose between various feasible solutions to the problem. Suppose we are dealing; with an anti-aircraft problem (cf. Fig. 1).

There might be two alternatives in the reckoning: solution A, based on guided weapons, and solution B, based on radar controlled guns; or alternatively, two guided weapons solutions; one based on command-to-line-of-sight, and one on semi-active homing.
The RAAF in the 1970s
Authors: Hannah Colin
Published: March 2023

On reflection, the development of the Royal Australian Air Force over the past 50 years may be considered to have taken place in three phases—the creation and slow growth of an air force as a distinct entity in the 1920s and 1930s, fostered in part by a series of daring transoceanic flights by both military and civilian aviators; the great expansion of the force during the Second World War which, in half a decade, transformed the RAAF from the biplane era to the jet age; and, finally, the restructuring and development of the force in the so-called post-war era but one, in fact, in which the RAAF has been required to participate in such military operations as confrontation with Indonesia, the anti-terrorist campaign in Malaya, limited war in Korea and the current pacification of South Vietnam.
A Carbon Fibre Vulcan Airbrake Flap
Authors: Fray J.
Published: March 2023

After an initial evaluation of the carbon fibres and matrix resins available at the time (1968) Hawker Siddeley Aviation embarked, under the sponsorship of the then Ministry of Technology, on the design and development of a number of representative aircraft structural components in order to gain experience of the overall problems involved and to give a lead in determining the direction of the necessary materials and process development programmes. An essential feature of this work was that the components produced should be cleared for extended flight trials so that not only would a good deal of useful service experience be gained but also many principles of quality and process control would be established and a platform for discussions with the various official bodies would be provided. In addition, by using the normal shop facilities for the manufacture of the components, it was hoped to introduce as many company personnel as possible to the new material.
A review of the development of Europa 2 inertial guidance
Authors: Cairns A. H.
Published: March 2023

The economic advantages of the Woomera Launch Site in South Australia that were all important in the initial formation of ELDO were, by 1966, outweighed by the limitations that the north pointing range imposed on future applications of the three stage Europa Launcher. The predominance of equatorial orbits (and, in particular, geostationary orbits) in the communications satellite field, demanded a near equatorial, east pointing range for efficient satellite launching.

To overcome this limitation on future Europa applications, a supplementary programme to establish an equatorial launch site (ELS) at Kourou in French Guyane, and to develop the Europa 2 launch vehicle for operations from the ELS, was therefore initiated in 1966.
Current and future implications of missile defence effectiveness on air strike missions
Authors: Jefferson G. R.
Published: March 2023

The subject of this paper is the interaction between airborne and ground attack missions by aircraft, and the defence systems now available to deny or counter such attacks. I should like to make it clear from the start that I am restricting myself to air operations in a non-nuclear land battle scenario and I speak not as an expert in attack missions, but rather in a historical and speculative fashion, as one who has been concerned with some of the techniques concerned with air defence.

You may, from me, expect a highly biased approach to the subject of the paper and probably you are right, but I should warn that if you expect me to conclude that the aircraft is doomed then I must reassure you that I believe that the aircraft remains a most flexible instrument of warfare and will for the foreseeable future exercise an extremely important position in the land and air battle.
The coming era of the quiet helicopter
Authors: Stuelpnagel Thomas R.
Published: March 2023

The subject of the quiet helicopter is receiving increasing attention throughout the world because it is now established that a helicopter can be made quiet. Quietening is also needed as more helicopters are being used over cities and residential areas. To date, little attention has been paid to helicopter quietening because the emphasis has been on achieving maximum payload and other performance. Now that the basic helicopter design has been established, refinements for quietening are becoming practical. The comparison is much like the evolution of the automobile and the truck in the city. Initially these vehicles were noisy. As their number increased and their design evolved, mufflers and sound-deadening materials were skilfully applied to reduce their noise to more acceptable levels for each type vehicle.
Surface to Air Guided Weapons (Naval)
Authors: Hampton P.
Published: March 2023

During the past ten years I have been involved in the development of Naval SAGW as leader of the Seacat, Seaslug and Sea Dart Project Teams within the RAE Weapons Department. The RAE's general responsibility has been that of co-ordinating R&D authority, plus being R&D authority for specific parts of the missile, but the detailed range of responsibility, plus its title, has varied from time to time and project to project.

In addition to the co-operation between the various project teams in Weapons Department we have across-the-board teams developing mathematical modelling techniques and programmes, and my colleagues from industry and the Royal Navy in the audience will note a familiar emphasis on modelling in my lecture.
ON THE CHARACTERISATION OF SPORADIC SIMPLE GROUPS BY CODEGREES
Authors: DOLORFINO MALLORY , MARTIN LUKE , SLONIM ZACHARY , SUN YUXUAN , YANG YONG
Published: March 2023

LetGbe a finite group and$\mathrm {Irr}(G)$the set of all irreducible complex characters ofG. Define the codegree of$\chi \in \mathrm {Irr}(G)$as$\mathrm {cod}(\chi ):={|G:\mathrm {ker}(\chi ) |}/{\chi (1)}$and denote by$\mathrm {cod}(G):=\{\mathrm {cod}(\chi ) \mid \chi \in \mathrm {Irr}(G)\}$the codegree set ofG. LetHbe one of the$26$sporadic simple groups. We show thatHis determined up to isomorphism by cod$(H)$.
THE SETTING OF GRATTIUS’CYNEGETICA
Authors: Wiseman T.P.
Published: March 2023

Nothing is known of the poet Grattius except that he was a contemporary of Ovid. However, certain peculiarities in the text of hisCynegeticasuggest that he wrote for public performance, that the poem was presented atludi scaeniciwhere dancers and singers were performing too, that the Palatine temple of Apollo was probably where the event took place, and that the most likely occasion for it was one of the ‘quinquennial’ games celebrating the defeat of Cleopatra.
Consumption of trematode parasite infectious stages: from conceptual synthesis to future research agenda
Authors: Koprivnikar J. , Thieltges D.W. , Johnson P.T.J.
Published: March 2023

Given their sheer cumulative biomass and ubiquitous presence, parasites are increasingly recognized as essential components of most food webs. Beyond their influence as consumers of host tissue, many parasites also have free-living infectious stages that may be ingested by non-host organisms, with implications for energy and nutrient transfer, as well as for pathogen transmission and infectious disease dynamics. This has been particularly well-documented for the cercaria free-living stage of digenean trematode parasites within the Phylum Platyhelminthes. Here, we aim to synthesize the current state of knowledge regarding cercariae consumption by examining: (a) approaches for studying cercariae consumption; (b) the range of consumers and trematode prey documented thus far; (c) factors influencing the likelihood of cercariae consumption; (d) consequences of cercariae consumption for individual predators (e.g. their viability as a food source); and (e) implications of cercariae consumption for entire communities and ecosystems (e.g. transmission, nutrient cycling and influences on other prey). We detected 121 unique consumer-by-cercaria combinations that spanned 60 species of consumer and 35 trematode species. Meaningful reductions in transmission were seen for 31 of 36 combinations that considered this; however, separate studies with the same cercaria and consumer sometimes showed different results. Along with addressing knowledge gaps and suggesting future research directions, we highlight how the conceptual and empirical approaches discussed here for consumption of cercariae are relevant for the infectious stages of other parasites and pathogens, illustrating the use of cercariae as a model system to help advance our knowledge regarding the general importance of parasite consumption.
Complete mitochondrial genome of Penicillidia jenynsii (Diptera: Hippoboscoidea: Nycteribiidae) and phylogenetic relationship
Authors: Yang Jinting , Huang Xiaobin , Wang Yujuan , Yang Huijuan , Zhang Xianzheng , Zheng Xiaoyan
Published: March 2023

In recent years, bat-associated pathogens, such as 2019 novel coronavirus, have been ravaging the world, and ectoparasites of bats have received increasing attention. Penicillidia jenynsii is a member of the family Nycteribiidae which is a group of specialized ectoparasites of bats. In this study, the complete mitochondrial genome of P. jenynsii was sequenced for the first time and a comprehensive phylogenetic analysis of the superfamily Hippoboscoidea was conducted. The complete mitochondrial genome of P. jenynsii is 16 165 base pairs (bp) in size, including 13 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes and 1 control region. The phylogenetic analysis based on 13 PCGs of the superfamily Hippoboscoidea known from the NCBI supported the monophyly of the family Nycteribiidae, and the family Nycteribiidae was a sister group with the family Streblidae. This study not only provided molecular data for the identification of P. jenynsii, but also provided a reference for the phylogenetic analysis of the superfamily Hippoboscoidea.
Tangential-force detection ability of three-axis fingernail-color sensor aided by CNN
Authors: Watanabe Keisuke , Chen Yandong , Komura Hiraku , Ohka Masahiro
Published: March 2023

We create a new tactile recording system with which we develop a three-axis fingernail-color sensor that can measure a three-dimensional force applied to fingertips by observing the change of the fingernail’s color. Since the color change is complicated, the relationships between images and three-dimensional forces were assessed using convolution neural network (CNN) models. The success of this method depends on the input data size because the CNN model learning requires big data. Thus, to efficiently obtain big data, we developed a novel measuring device, which was composed of an electronic scale and a load cell, to obtain fingernail images with 0
$^\circ$
to 360
$^\circ$
directional tangential force. We performed a series of evaluation experiments to obtain movies of the color changes caused by the three-axis forces and created a data set for the CNN models by transforming the movies to still images. Although we produced a generalized CNN model that can evaluate the images of any person’s fingernails, its root means square error (RMSE) exceeded both the whole and individual models, and the individual models showed the smallest RMSE. Therefore, we adopted the individual models, which precisely evaluated the tangential-force direction of the test data in an
$F_x$
-
$F_y$
plane within around
$\pm$
2.5
$^\circ$
error at the peak points of the applied force. Although the fingernail-color sensor possessed almost the same level of accuracy as previous sensors for normal-force tests, the present fingernail-color sensor acts as the best tangential sensor because the RMSE obtained from tangential-force tests was around 1/3 that of previous studies.
Creating Law through Regulating Intimacy: The Case of Slave Marriage in Nineteenth-Century New York and the United States
Authors: Feldman Lauren
Published: March 2023

This article argues that American jurists fashioned new understandings about the capacity of states to legislate about marriage through regulating the intimate lives of enslaved and newly freed individuals. This article does so through analyzing the creation and impact of a little-studied 1809 law in New York that legalized the marriages of enslaved people—while individuals were still enslaved—as part of the state's process of gradual emancipation, which occurred from 1799 to 1827. In New York, by legalizing enslaved people's marriages, jurists privatized financial liabilities within soon-to-be freed families. The law stood at odds with national juridical understanding about marital regulation. Jurists in the early republic were uncertain about whether states could legislate about matrimony. Southern states after the Civil War then cited and replicated New York's logic in legislating to legalize the marriages of freedpeople, similarly privatizing financial claims within families. In the cases of both New York and national emancipation, jurists, in choosing privatization, foreclosed possibilities for a different or broader vision of state support for freedpeople, such as reparations. After making marital laws about slavery, both New York and Southern states created and/or tightened their marriage laws, further inscribing understandings of the marital family into American governance. This piece contributes to historiographies of slavery, the American state, and intimacy.
The Interweaving: Communist Women and Feminism in 1970s Italy
Authors: Strazzeri Victor
Published: March 2023

The Italian Communist Party's peak of popularity in the mid-1970s, during its so-called ‘Eurocommunist’ turn, coincided with a surge of feminist struggles in Italy. While scholarship has treated Communist Party politics and feminism as unrelated historical phenomena, this article provides evidence for their multi-layered ‘interweaving’. The term was employed by PCI women themselves to conceptualise how struggles against social and gender inequalities interlock, but also to stress that overcoming women's oppression in Italian society (and beyond) presupposed a reckoning with male dominance – and the peripheral role of the ‘women's question’ – within their party. The ensuing intra-party debate, reconstructed through sources from the turning-point year of 1976, is a revealing instance of PCI activists’ reception of 1970s feminism.
New Histories of Law and Rights in Twentieth-Century Germany
Authors: Gehrig Sebastian
Published: March 2023

On 1 March 2022, German Foreign Minister Annalena Baerbock accused the Russian President Vladimir Putin's government of waging a war of aggression against Ukraine. Speaking at the General Assembly of the United Nations (UN), she drew explicit links to the Nazi war of aggression in order to legitimise sanctions against Russia as she stressed the UN's mission to work for peace enshrined in the UN charter. Twelve months earlier, in February 2021, the Higher Regional Court in Koblenz sentenced a forty-four-year-old Syrian citizen to four and a half years’ imprisonment. Based on the ‘shared values of humanity’, the verdict made headlines as the court explicitly cited the universal jurisdiction principle enshrined in the Völkerstrafgesetzbuch (VStGB) that had been enacted in 2002 to bring German law into accordance with the Rome Statute of the International Criminal Court.1 Since 2002, German courts have adopted these international law principles and legal norms in a series of legal actions against foreigners to prosecute crimes against humanity.
Sex differences in Parkinson disease-associated episodic memory and processing speed deficits
Authors: Reekes Tyler H. , Higginson Christopher I. , Sigvardt Karen A. , King David S. , Levine Dawn , Wheelock Vicki L. , Disbrow Elizabeth A.
Published: March 2023

Objectives:

This study aims to address a gap in the data on cognitive sex differences in persons living with Parkinson disease (PD). There is some evidence that cognitive dysfunction is more severe in male PD, however data on episodic memory and processing speed is incomplete.

Methods:

One hundred and sixty-seven individuals with a diagnosis of PD were included in this study. Fifty-six of those individuals identified as female. The California Verbal Learning Test 1st edition and the Wechsler Memory Scale 3rd edition were used to evaluate verbal and visuospatial episodic memory and the Wechsler Adult Intelligence Scale 3rd edition was used to evaluate processing speed. Multivariate analysis of covariance was used to identify sex-specific differences across groups.

Results:

Our results show that males with PD performed significantly worse than females in verbal and visuospatial recall as well as a trend for the processing speed task of coding.

Conclusions:

Our finding of superior performance among females with PD in verbal episodic memory is consistent with reports in both healthy and PD individuals; however, females outperforming males in measures of visuospatial episodic memory is unique to PD. Cognitive deficits preferentially affecting males appear to be associated with frontal lobe-related function. Therefore, males may represent a disease subgroup more susceptible to disease mechanisms affecting frontal lobe deterioration and cognitive disturbances in PD.
Melting Alpine Water Towers Aggravate Downstream Low Flows: A Stress‐Test Storyline Approach
Authors: van Tiel Marit , Weiler Markus , Freudiger Daphné , Moretti Greta , Kohn Irene , Gerlinger Kai , Stahl Kerstin
Published: March 2023

Droughts can lead to extreme low flow situations in rivers, with resulting severe impacts. Upstream snow and ice melt in many of the world's mountain water towers can alleviate the hydrological consequences of drought, yet global warming threatens the cryosphere. To improve the understanding of melt water contributions during drought in the case of future glacier retreat, we developed stress‐test storyline scenarios to model streamflow and tested them in the European river Rhine basin. Meteorological conditions of past drought and low flow years in Europe, 1976, 2003, and 2018, were repeated at three future moments in time, representing nowadays, near future and far future conditions. The latter two conditions were obtained by climate projections under the RCP8.5 scenario. Results show that the low flow situations caused by the meteorological drought situations aggravate in future conditions, more so for the far future and for the year 2003 because of the relatively large glacier ice melt contribution in the past. Summer (July–September) streamflow may decline by 5%–25% far downstream and 30%–70% upstream and the duration of extreme low flow situations may double compared to the selected past drought events. These results are relevant for the Rhine as a major European river but stand exemplary for many other river basins and highlight the importance of cryospheric changes for downstream low flow situations in a changing climate. The stress‐test scenarios allow a glimpse into future extreme low flow events aiding adaptation planning, and might be adapted to include other important low flow drivers.
The Redox State of Incipient Oceanic Subduction Zones: An Example From the Troodos Ophiolite (Cyprus)
Authors: Hu Wen‐Jun , Zhou Mei‐Fu , Ribeiro Julia M. , Malpas John , Wu Ya‐Dong , Bai Zhong‐Jie
Published: March 2023

To understand the oxygen fugacity (fO2) during subduction initiation, we examined proto‐arc boninites and associated mantle peridotites from the Troodos ophiolite, Cyprus. The Troodos ophiolite represents an exhumed piece of oceanic lithosphere that formed during subduction initiation in Neo‐Tethys in Late Cretaceous. Dunites and surrounding harzburgites in the Kokkinorotsos podiform chromite deposit of the ophiolite were formed by reactions between peridotites and ascending boninitic magmas. The olivine‐chromite oxybarometers show that the fO2 values (∆QFM −0.41 ± 0.37) of the dunites are slightly higher than those (∆QFM −0.85 ± 0.52) of the harzburgites under mantle conditions, indicating that the mantle fO2 was raised limitedly by percolation of the boninitic magmas. Meanwhile, the boninitic upper pillow lavas in the Margi area also recorded relatively reduced fO2 values (∆QFM −0.52 ± 0.20) during olivine‐chromite crystallization, comparable to the fO2 of mid‐ocean ridge basalts. Shallow‐level processes (i.e., magma ascent, crystallization, crustal assimilation, and degassing) appear to have limited influence on the estimated fO2 values in Troodos. The similarly low fO2 values of the mantle peridotites and boninitic magmas suggest that the Troodos primary boninitic magmas were perhaps not as oxidized as the Izu‐Bonin‐Mariana (IBM) proto‐arc boninitic magmas, though both mantle sources have captured the slab fluids released during subduction inception. This difference might be attributed to the different nature of the slab components (i.e., a more reduced subduction input for Troodos). Our study thus suggests that subducted slabs might not always release oxidized fluids, and the oxidation processes might be different for each nascent subduction zones.
The Thermosphere Is a Drag: The 2022 Starlink Incident and the Threat of Geomagnetic Storms to Low Earth Orbit Space Operations
Authors: Berger T. E. , Dominique M. , Lucas G. , Pilinski M. , Ray V. , Sewell R. , Sutton E. K. , Thayer J. P. , Thiemann E.
Published: March 2023

On 03 February 2022, SpaceX launched 49 Starlink satellites, 38 of which re‐entered the atmosphere on or about 07 February 2022 due to unexpectedly high atmospheric drag. We use empirical model (NRLMSIS, JB08, and HASDM) outputs as well as solar extreme ultraviolet occultation and high‐fidelity accelerometer data to show that thermospheric density was at least 20%–30% higher at 210 km relative to the 9 days prior to the launch due to consecutive geomagnetic storms related to solar eruptions from NOAA AR12936 on 29 January 2022. We model the orbital altitude and in‐track position of a Starlink‐like satellite in a low‐drag configuration at 200 km during minor (G1) and extreme (G5) geomagnetic storms to show that an extreme storm would have at least a factor of two higher impact, with cumulative in‐track errors on the order of 10,000 km after a 5‐day duration extreme storm. Comparison of the JB08 and NRL MSIS models relative to the HASDM model during modeled historical minor and extreme geomagnetic storms shows that in‐track errors on the order of 100 km per day at 250 km, decreasing to cumulative errors on the order of 1 km per day at 550 km during geomagnetic storms. We conclude that full‐physics, data assimilative, coupled models of the magnetosphere and upper atmosphere, as well as new operational satellite missions providing “nowcasting” data to launch controllers, space traffic coordinators, and satellite operators, are needed to prevent similar—or worse—orbital system impacts during future geomagnetic storms.
Cross-diagnostic determinants of cognitive functioning: the muscarinic cholinergic receptor as a model system
Authors: Jones Sara E. , Harvey Philip D.
Published: March 2023

Cognitive impairment is a predictor of disability across different neuropsychiatric conditions, and cognitive abilities are also strongly related to educational attainment and indices of life success in the general population. Previous attempts at drug development for cognitive enhancement have commonly attempted to remedy defects in transmitters systems putatively associated with the conditions of interest such as the glutamate system in schizophrenia. Recent studies of the genomics of cognitive performance have suggested influences that are common in the general population and in different neuropsychiatric conditions. Thus, it seems possible that transmitter systems that are implicated for cognition across neuropsychiatric conditions and the general population would be a viable treatment target. We review the scientific data on cognition and the muscarinic cholinergic receptor system (M1 and M4) across different diagnoses, in aging, and in the general population. We suggest that there is evidence suggesting potential beneficial impacts of stimulation of critical muscarinic receptors for the enhancement of cognition in a broad manner, as well as the treatment of psychotic symptoms. Recent developments make stimulation of the M1 receptor more tolerable, and we identify the potential benefits of M1 and M4 receptor stimulation as a trans-diagnostic treatment model.
A T follicular helper cell origin for T regulatory type 1 cells
Authors: Solé Patricia , Yamanouchi Jun , Garnica Josep , Uddin Muhammad Myn , Clarke Robert , Moro Joel , Garabatos Nahir , Thiessen Shari , Ortega Mireia , Singha Santiswarup , Mondal Debajyoti , Fandos César , Saez-Rodriguez Julio , Yang Yang , Serra Pau , Santamaria Pere
Published: March 2023

Chronic antigenic stimulation can trigger the differentiation of antigen-experienced CD4+ T cells into T regulatory type 1 (TR1) cells, a subset of interleukin-10-producing Treg cells that do not express FOXP3. The identities of the progenitor(s) and transcriptional regulators of this T-cell subset remain unclear. Here, we show that the peptide-major histocompatibility complex class II (pMHCII) monospecific immunoregulatory T-cell pools that arise in vivo in different genetic backgrounds in response to pMHCII-coated nanoparticles (pMHCII-NPs) are invariably comprised of oligoclonal subpools of T follicular helper (TFH) and TR1 cells with a nearly identical clonotypic composition but different functional properties and transcription factor expression profiles. Pseudotime analyses of scRNAseq data and multidimensional mass cytometry revealed progressive downregulation and upregulation of TFH and TR1 markers, respectively. Furthermore, pMHCII-NPs trigger cognate TR1 cell formation in TFH cell-transfused immunodeficient hosts, and T-cell-specific deletion of Bcl6 or Irf4 blunts both the TFH expansion and TR1 formation induced by pMHCII-NPs. In contrast, deletion of Prdm1 selectively abrogates the TFH-to-TR1 conversion. Bcl6 and Prdm1 are also necessary for anti-CD3 mAb-induced TR1 formation. Thus, TFH cells can differentiate into TR1 cells in vivo, and BLIMP1 is a gatekeeper of this cellular reprogramming event.
Deep learning-enabled segmentation of ambiguous bioimages with deepflash2
Authors: Griebel Matthias , Segebarth Dennis , Stein Nikolai , Schukraft Nina , Tovote Philip , Blum Robert , Flath Christoph M.
Published: March 2023

Bioimages frequently exhibit low signal-to-noise ratios due to experimental conditions, specimen characteristics, and imaging trade-offs. Reliable segmentation of such ambiguous images is difficult and laborious. Here we introduce deepflash2, a deep learning-enabled segmentation tool for bioimage analysis. The tool addresses typical challenges that may arise during the training, evaluation, and application of deep learning models on ambiguous data. The tool’s training and evaluation pipeline uses multiple expert annotations and deep model ensembles to achieve accurate results. The application pipeline supports various use-cases for expert annotations and includes a quality assurance mechanism in the form of uncertainty measures. Benchmarked against other tools, deepflash2 offers both high predictive accuracy and efficient computational resource usage. The tool is built upon established deep learning libraries and enables sharing of trained model ensembles with the research community. deepflash2 aims to simplify the integration of deep learning into bioimage analysis projects while improving accuracy and reliability.
Seismic evidence for a 1000 km mantle discontinuity under the Pacific
Authors: Zhang Zhendong , Irving Jessica C. E. , Simons Frederik J. , Alkhalifah Tariq
Published: March 2023

Seismic discontinuities in the mantle are indicators of its thermo-chemical state and offer clues to its dynamics. Ray-based seismic methods, though limited by the approximations made, have mapped mantle transition zone discontinuities in detail, but have yet to offer definitive conclusions on the presence and nature of mid-mantle discontinuities. Here, we show how to use a wave-equation-based imaging method, reverse-time migration of precursors to surface-reflected seismic body waves, to uncover both mantle transition zone and mid-mantle discontinuities, and interpret their physical nature. We observe a thinned mantle transition zone southeast of Hawaii, and a reduction in impedance contrast around 410 km depth in the same area, suggesting a hotter-than-average mantle in the region. Here, we furthermore reveal a 4000–5000 km-wide reflector in new images of the mid mantle below the central Pacific, at 950–1050 km depth. This deep discontinuity exhibits strong topography and generates reflections with polarity opposite to those originating at the 660 km discontinuity, implying an impedance reversal near 1000 km. We link this mid-mantle discontinuity to the upper reaches of deflected mantle plumes upwelling in the region. Reverse-time migration full-waveform imaging is a powerful approach to imaging Earth’s interior, capable of broadening our understanding of its structure and dynamics and shrinking modeling uncertainties.
Top-down patterning of topological surface and edge states using a focused ion beam
Authors: Bake Abdulhakim , Zhang Qi , Ho Cong Son , Causer Grace L. , Zhao Weiyao , Yue Zengji , Nguyen Alexander , Akhgar Golrokh , Karel Julie , Mitchell David , Pastuovic Zeljko , Lewis Roger , Cole Jared H. , Nancarrow Mitchell , Valanoor Nagarajan , Wang Xiaolin , Cortie David
Published: March 2023

The conducting boundary states of topological insulators appear at an interface where the characteristic invariant ℤ2 switches from 1 to 0. These states offer prospects for quantum electronics; however, a method is needed to spatially-control ℤ2 to pattern conducting channels. It is shown that modifying Sb2Te3 single-crystal surfaces with an ion beam switches the topological insulator into an amorphous state exhibiting negligible bulk and surface conductivity. This is attributed to a transition from ℤ2 = 1 → ℤ2 = 0 at a threshold disorder strength. This observation is supported by density functional theory and model Hamiltonian calculations. Here we show that this ion-beam treatment allows for inverse lithography to pattern arrays of topological surfaces, edges and corners which are the building blocks of topological electronics.
Epigenetic and transcriptomic characterization reveals progression markers and essential pathways in clear cell renal cell carcinoma
Authors: Wu Yige , Terekhanova Nadezhda V. , Caravan Wagma , Naser Al Deen Nataly , Lal Preet , Chen Siqi , Mo Chia-Kuei , Cao Song , Li Yize , Karpova Alla , Liu Ruiyang , Zhao Yanyan , Shinkle Andrew , Strunilin Ilya , Weimholt Cody , Sato Kazuhito , Yao Lijun , Serasanambati Mamatha , Yang Xiaolu , Wyczalkowski Matthew , Zhu Houxiang , Zhou Daniel Cui , Jayasinghe Reyka G. , Mendez Daniel , Wendl Michael C. , Clark David , Newton Chelsea , Ruan Yijun , Reimers Melissa A. , Pachynski Russell K. , Kinsinger Chris , Jewell Scott , Chan Daniel W. , Zhang Hui , Chaudhuri Aadel A. , Chheda Milan G. , Humphreys Benjamin D. , Mesri Mehdi , Rodriguez Henry , Hsieh James J. , Ding Li , Chen Feng
Published: March 2023

Identifying tumor-cell-specific markers and elucidating their epigenetic regulation and spatial heterogeneity provides mechanistic insights into cancer etiology. Here, we perform snRNA-seq and snATAC-seq in 34 and 28 human clear cell renal cell carcinoma (ccRCC) specimens, respectively, with matched bulk proteogenomics data. By identifying 20 tumor-specific markers through a multi-omics tiered approach, we reveal an association between higher ceruloplasmin (CP) expression and reduced survival.CPknockdown, combined with spatial transcriptomics, suggests a role for CP in regulating hyalinized stroma and tumor-stroma interactions in ccRCC. Intratumoral heterogeneity analysis portrays tumor cell-intrinsic inflammation and epithelial-mesenchymal transition (EMT) as two distinguishing features of tumor subpopulations. Finally,BAP1mutations are associated with widespread reduction of chromatin accessibility, whilePBRM1 mutations generally increase accessibility, with the former affecting five times more accessible peaks than the latter. These integrated analyses reveal the cellular architecture of ccRCC, providing insights into key markers and pathways in ccRCC tumorigenesis.
Mechanism of antibody-specific deglycosylation and immune evasion by Streptococcal IgG-specific endoglycosidases
Authors: Trastoy Beatriz , Du Jonathan J. , Cifuente Javier O. , Rudolph Lorena , García-Alija Mikel , Klontz Erik H. , Deredge Daniel , Sultana Nazneen , Huynh Chau G. , Flowers Maria W. , Li Chao , Sastre Diego E. , Wang Lai-Xi , Corzana Francisco , Mallagaray Alvaro , Sundberg Eric J. , Guerin Marcelo E.
Published: March 2023

Bacterial pathogens have evolved intricate mechanisms to evade the human immune system, including the production of immunomodulatory enzymes. Streptococcus pyogenes serotypes secrete two multi-modular endo-β-N-acetylglucosaminidases, EndoS and EndoS2, that specifically deglycosylate the conserved N-glycan at Asn297 on IgG Fc, disabling antibody-mediated effector functions. Amongst thousands of known carbohydrate-active enzymes, EndoS and EndoS2 represent just a handful of enzymes that are specific to the protein portion of the glycoprotein substrate, not just the glycan component. Here, we present the cryoEM structure of EndoS in complex with the IgG1 Fc fragment. In combination with small-angle X-ray scattering, alanine scanning mutagenesis, hydrolytic activity measurements, enzyme kinetics, nuclear magnetic resonance and molecular dynamics analyses, we establish the mechanisms of recognition and specific deglycosylation of IgG antibodies by EndoS and EndoS2. Our results provide a rational basis from which to engineer novel enzymes with antibody and glycan selectivity for clinical and biotechnological applications.
CEP peptide and cytokinin pathways converge on CEPD glutaredoxins to inhibit root growth
Authors: Taleski Michael , Chapman Kelly , Novák Ondřej , Schmülling Thomas , Frank Manuel , Djordjevic Michael A.
Published: March 2023

C-TERMINALLY ENCODED PEPTIDE (CEP) and cytokinin hormones act over short and long distances to control plant responses to environmental cues. CEP and cytokinin pathway mutants share phenotypes, however, it is not known if these pathways intersect. We show that CEP and cytokinin signalling converge on CEP DOWNSTREAM (CEPD) glutaredoxins to inhibit primary root growth. CEP inhibition of root growth was impaired in mutants defective in trans-zeatin (tZ)-type cytokinin biosynthesis, transport, perception, and output. Concordantly, mutants affected in CEP RECEPTOR 1 showed reduced root growth inhibition in response to tZ, and altered levels of tZ-type cytokinins. Grafting and organ-specific hormone treatments showed that tZ-mediated root growth inhibition involved CEPD activity in roots. By contrast, root growth inhibition by CEP depended on shoot CEPD function. The results demonstrate that CEP and cytokinin pathways intersect, and utilise signalling circuits in separate organs involving common glutaredoxin genes to coordinate root growth.
Large haploblocks underlie rapid adaptation in the invasive weed Ambrosia artemisiifolia
Authors: Battlay Paul , Wilson Jonathan , Bieker Vanessa C. , Lee Christopher , Prapas Diana , Petersen Bent , Craig Sam , van Boheemen Lotte , Scalone Romain , de Silva Nissanka P. , Sharma Amit , Konstantinović Bojan , Nurkowski Kristin A. , Rieseberg Loren H. , Connallon Tim , Martin Michael D. , Hodgins Kathryn A.
Published: March 2023

Adaptation is the central feature and leading explanation for the evolutionary diversification of life. Adaptation is also notoriously difficult to study in nature, owing to its complexity and logistically prohibitive timescale. Here, we leverage extensive contemporary and historical collections of Ambrosia artemisiifolia—an aggressively invasive weed and primary cause of pollen-induced hayfever—to track the phenotypic and genetic causes of recent local adaptation across its native and invasive ranges in North America and Europe, respectively. Large haploblocks—indicative of chromosomal inversions—contain a disproportionate share (26%) of genomic regions conferring parallel adaptation to local climates between ranges, are associated with rapidly adapting traits, and exhibit dramatic frequency shifts over space and time. These results highlight the importance of large-effect standing variants in rapid adaptation, which have been critical to A. artemisiifolia’s global spread across vast climatic gradients.