bluuebunny/crossref_metadata_2025_split huggingface dataset:
American Helicopter Development
Authors: Siltanen Major John 
Published: October 2023

Members who were fortunate enough to be able to attend the Association’s Meeting on January 24th were rewarded by a most illuminating lecture on American Helicopter Development, delivered by MAJOR J C SILTANEN of the U S A A FMAJOR SILTANEN is here in the capacity of Air Technical Liaison Officer to the U S Military Attache in London, in America he was engaged on work with the Rotary-wing Branch at Wright Field, being closely concerned with the military development of Sikorsky HelicoptersThe lecture took the form of an informal discourse illustrated by many interesting slides, most of which have since been published in the Aeronautical Press, receiving due credit In token of the esteem in which we hold MAJOR SILTANEN, the Council have elected him an Honorary Member during his term of office in this country
Some Economics of the Helicopter — Present and Future
Authors: Wigdortchik L S 
Published: October 2023

Ladies and GentlemenThe subject of the opening paper for our 1948/49 Lecture Session is, I am sure you will agree, of prime importance to all of us in the helicopter industry To my mind there is no point in spending time, money and energy designing and constructing helicopters unless they can be operated economically, although for any specialized application economy may not be so importantMR WIGDORTCHIK has put a great deal of work in the preparation of this paper, and although he will only have time to read a summary this afternoon, examination of the full paper, which will be published in the Association’s Journal, will be well worth whileMR WIGDORTCHIK is an A F R Ae S, and was a Wakefield Scholar to the College of Aeronautical Engineering in London He was commissioned in the Technical Branch of the R A F in 1940, and from 1943 was engaged in Research and Development in connection with aircraft, and subsequently helicopters, holding an appointment in the Ministry of Supply in this respect
A Brief Survey of Characteristic Vibration Sources in Helicopters
Authors: Shapiro J 
Published: October 2023

Rotor Unbalance Rotor unbalance is a once per rev impulse This is a case of clear separation of impulse and response Unbalance is a rotating force Its origin can be mass unbalance of blades or geometric dissymmetry in their distribution which can be caused by (a) unequal pitch, (b) errors in the geometry of articulation, (c) unequal damper settings Unequal pitch can occur in spite of equal pitch settmg if the elastic twists are unequal due to unequal pitching moments In practice these are mainly aerodynamic moments which can be corrected with tabs or avoided by superprecision in blade makingResponse depends on rotor mountings Rotor r p m must be removed from the natural frequency of the hub on its mountings Subcntical and supercritical mountings are practical Supercritical mountings due to the isolation of the rotor system are mostly introduced for other reasons (discussed below)
Some Aerodynamic Aspects of Rotor Blade Design
Authors: Squire H B 
Published: October 2023

In studying the aerodynamics of rotor blades we are often uncertain how far we may apply quantitatively the data obtained from wind tunnel tests of aerofoils Of course, the rotor blade behaves qualitatively like an aerofoil, but I sometimes feel doubtful about calculations of the effect of detailed changes in blade design, say for example, the effect of taper on performance, and wish to stress the desirability of wind tunnel tests by which some at least of these questions could be settled more easily than by flight testsI have found in preparing this lecture that covering the whole field would be impracticable I intend to concentrate mainly on the compressibility problem which, closely associated with stalling, seems to me to be the principal aerodynamic problem facing the blade designer today
The Future Employment of the 40-Seater Helicopter and the need for Dispersing Air Liners to Airstrips Round Britain's Coasts
Authors: Courtenay William 
Published: October 2023

Before 1960 we should be in a position to inaugurate services of large size 40/45 seater Helicopters probably cruising at a minimum of 150 m p h These could be used to cope with passenger traffic to and from city centres and coastal airstripsHitherto during the first 30 years of our Civil Aviation we have been compelled to concentrate air traffic into one Airport for London First Croydon and then Heath Row were selected The coming of the Helicopter is going to provide a unique opportunity for dispersing air traffic away from busy cities to coastal airstrips It is suggested that the most careful study be given to this novel plan for dispersal as against the dangers of continued concentration The traffic for instance, attracted by British Overseas Airways Corporation through tourism as well as by their excellent Service, through the first two months of cut rate traffic (May and June, 1952) rose 37 per cent above the comparable period of 1950 It might have been even higher had not the oil strike m U S A restricted allotment of fuel
Convertible Aircraft
Authors: Liptrot R. N. 
Published: October 2023

THE CHAIRMAN: This afternoon I take the Chair with great pleasure for the occasion is marked by the presence of our friend, Major G. P. BULMAN, President of the Royal Aeronautical Society, and also other .members of the Society, who have come along to hear Captain LIPTROT. I know that you will support me in extending to Major BULMAN a very warm welcome. It is the second occasion on which we have been able to meet on common ground, and I know that we shall enjoy listening to Captain LIPTROT on this particular subject.We have been told that certain of our lectures in the past have been far too technical and above the understanding of some of the more youthful of our membership, and I must say that sometimes even I have viewed with apprehension the mass of mathematical formulae presented by some of our more advanced lecturers, but today I am heartened because our old friend Captain LIPTROT is the lecturer and he is one of those who, although accomplished technically, is able to present his subject in an exciting and yet easily understandable manner, having a style which brings the subject well within my own comprehension.
Helicopter Maintenance for the Non-Regular Schedule Operator
Authors: Bristow Alan E. 
Published: October 2023

Let me make it quite clear at the beginning that I am not speaking as a paid agent or employee of any Hiller operator or representative, and that what I have to say is an expression of my personal opinions. They are based on over 2,000 hours of commercial operations with the Hiller 360 all over Europe, North and West Africa, during the past twelve months, when as Technical Manager of Helicop-Air (Paris) it was one of my responsibilities to ensure the efficient maintenance of three and sometimes four machines on high utilisation work.Our efforts were directed principally towards such profit-making enterprises as insecticide spraying and dusting of cultivated crops, forests, swamps and river beds; the operation of a pilot and engineer training school; publicity flying for large manufacturing firms; a non-schedule passenger service; and sales demonstration.These operations were frequently in widely dispersed, remote and inaccessible places where maintenance installations and workshop facilities were non-existent.
Accessibility, Servicing and Testing of Components
Authors: Walker G. E. 
Published: October 2023

Prototype helicopters at the Bristol Aeroplane Company have been produced and servicing schedules have been made up detailing the maintenance work and inspection that has to be carried out after the following periods : (a) between flights, (b) daily, and (c) after 30, 60, 120 and 240 hours flying.At the time these schedules were made it was not fully realised that the work would not be carried out exactly in this way.We now learn that the airline operators are dividing their 30, 60, 120 and 240 hour inspection and maintenance schedules into small parts. One of these parts is added to the routine daily inspection, and so, by the time 240 hours of flying have been completed the whole of the interim schedules have also been completed, without withdrawing the helicopter from service. This system can only be operated providing that all work in the schedules can be split into tasks of less than, say, three hours each; there must, of course, be exceptions as obviously the overhauling of an engine takes longer than three hours.
On the Role of Continuing Currents in Lightning‐Induced Fire Ignition
Authors: Pérez‐Invernón Francisco J. , Moris Jose V. , Gordillo‐Vázquez Francisco J. , Füllekrug Martin , Pezzatti Gianni Boris , Conedera Marco , Lapierre Jeff , Huntrieser Heidi 
Published: October 2023

AbstractLightning flashes are an important source of wildfires worldwide, contributing to the emission of trace gases to the atmosphere. Based on experiments and field observations, continuing currents in lightning have since a long time been proposed to play a significant role in the ignition of wildfires. However, simultaneous detections of optical and radio signals from fire‐igniting lightning confirming the role of continuing currents in igniting wildfires are rare. In this work, we first analyze the optical signal of the lightning‐ignited wildfires reported by the Geostationary Lightning Mapper over the Contiguous United States (CONUS) during the summer of 2018, and we then analyze the optical and the Extremely Low Frequency signal of a confirmed fire‐igniting lightning flash in the Swiss Alps. Despite data uncertainties, we found that the probability of ignition of a lightning flash with Continuing Current (CC) lasting more than 10 ms is higher than that of cloud‐to‐ground lightning in CONUS. Finally, we confirm the existence of a long CC (lasting about 400 ms) associated with a long‐lasting optical signal (lasting between 2 and 4 s) of a video‐recorded fire‐igniting lightning flash.
Strain-level diversity of symbiont communities between individuals and populations of a bioluminescent fish
Authors: Gould A L , Donohoo S A , Román E D , Neff E E 
Published: October 2023

Abstract
The bioluminescent symbiosis involving the urchin cardinalfish, Siphamia tubifer, and Photobacterium mandapamensis, a luminous member of the Vibrionaceae, is highly specific compared to other bioluminescent fish-bacteria associations. Despite this high degree of specificity, patterns of genetic diversity have been observed for the symbionts from hosts sampled over relatively small spatial scales. We characterized and compared sub-species, strain-level symbiont diversity within and between S. tubifer hosts sampled from the Philippines and Japan using PCR fingerprinting. We then carried out whole genome sequencing of the unique symbiont genotypes identified to characterize the genetic diversity of the symbiont community and the symbiont pangenome. We determined that an individual light organ contains six symbiont genotypes on average, but varied between 1–13. Additionally, we found that there were few genotypes shared between hosts from the same location. A phylogenetic analysis of the unique symbiont strains indicated location-specific clades, suggesting some genetic differentiation in the symbionts between host populations. We also identified symbiont genes that were variable between strains, including luxF, a member of the lux operon, which is responsible for light production. We quantified the light emission and growth rate of two strains missing luxF along with the other strains isolated from the same light organs and determined that strains lacking luxF were dimmer but grew faster than most of the other strains, suggesting a potential metabolic trade-off. This study highlights the importance of strain-level diversity in microbial associations and provides new insight into the underlying genetic architecture of intraspecific symbiont communities within a host.
An appetite for aggressive behavior? Female rats, too, derive reward from winning aggressive interactions
Authors: Börchers Stina , Carl Jil , Schormair Katharina , Krieger Jean-Philippe , Asker Mohammed , Edvardsson Christian E. , Jerlhag Elisabeth , Skibicka Karolina P. 
Published: October 2023

AbstractWhile aggression is an adaptive behavior mostly triggered by competition for resources, it can also in and of itself be rewarding. Based on the common notion that female rats are not aggressive, much of aggression research has been centered around males, leading to a gap in the understanding of the female aggression neurobiology. Therefore, we asked whether intact virgin female rats experience reward from an aggressive interaction and assessed aggression seeking behavior in rats of both sexes. To validate the involvement of reward signaling, we measured mesolimbic dopamine turnover and determined the necessity of dopamine signaling for expression of aggression-seeking. Together our data indicate that female rats exhibit aggressive behavior outside of maternal context, experience winning aggressive behaviors as rewarding, and do so to a similar extent as male rats and in a dopamine-dependent manner.
Effectiveness of the second COVID-19 booster against Omicron: a large-scale cohort study in Chile
Authors: Jara Alejandro , Cuadrado Cristobal , Undurraga Eduardo A. , García Christian , Nájera Manuel , Bertoglia María Paz , Vergara Verónica , Fernández Jorge , García-Escorza Heriberto , Araos Rafael 
Published: October 2023

AbstractIn light of the ongoing COVID-19 pandemic and the emergence of new SARS-CoV-2 variants, understanding the effectiveness of various booster vaccination regimens is pivotal. In Chile, using a prospective national cohort of 3.75 million individuals aged 20 or older, we evaluate the effectiveness against COVID-19-related intensive care unit (ICU) admissions and death of mRNA-based second vaccine boosters for four different three-dose background regimes: BNT162b2 primary series followed by a homologous booster, and CoronaVac primary series followed by an mRNA booster, a homologous booster, and a ChAdOx-1 booster. We estimate the vaccine effectiveness weekly from February 14 to August 15, 2022, by determining hazard ratios of immunization over non-vaccination, accounting for relevant confounders. The overall adjusted effectiveness of a second mRNA booster shot is 88.2% (95%CI, 86.2–89.9) against ICU admissions and 90.5% (95%CI 89.4–91.4) against death. Vaccine effectiveness shows a mild decrease for all regimens and outcomes, probably linked to the introduction of BA.4 and BA.5 Omicron sub-lineages and the waning of immunity. Based on our findings, individuals might not need additional boosters for at least 6 months after receiving a second mRNA booster shot in this setting.
CRISPR-Cas9 engineering of the RAG2 locus via complete coding sequence replacement for therapeutic applications
Authors: Allen Daniel , Knop Orli , Itkowitz Bryan , Kalter Nechama , Rosenberg Michael , Iancu Ortal , Beider Katia , Lee Yu Nee , Nagler Arnon , Somech Raz , Hendel Ayal 
Published: October 2023

AbstractRAG2-SCID is a primary immunodeficiency caused by mutations in Recombination-activating gene 2 (RAG2), a gene intimately involved in the process of lymphocyte maturation and function. ex-vivo manipulation of a patient’s own hematopoietic stem and progenitor cells (HSPCs) using CRISPR-Cas9/rAAV6 gene editing could provide a therapeutic alternative to the only current treatment, allogeneic hematopoietic stem cell transplantation (HSCT). Here we show an innovative RAG2 correction strategy that replaces the entire endogenous coding sequence (CDS) for the purpose of preserving the critical endogenous spatiotemporal gene regulation and locus architecture. Expression of the corrective transgene leads to successful development into CD3+TCRαβ+ and CD3+TCRγδ+ T cells and promotes the establishment of highly diverse TRB and TRG repertoires in an in-vitro T-cell differentiation platform. Thus, our proof-of-concept study holds promise for safer gene therapy techniques of tightly regulated genes.
Reconstructing disease dynamics for mechanistic insights and clinical benefit
Authors: Frishberg Amit , Milman Neta , Alpert Ayelet , Spitzer Hannah , Asani Ben , Schiefelbein Johannes B. , Bakin Evgeny , Regev-Berman Karen , Priglinger Siegfried G. , Schultze Joachim L. , Theis Fabian J. , Shen-Orr Shai S. 
Published: October 2023

AbstractDiseases change over time, both phenotypically and in their underlying molecular processes. Though understanding disease progression dynamics is critical for diagnostics and treatment, capturing these dynamics is difficult due to their complexity and the high heterogeneity in disease development between individuals. We present TimeAx, an algorithm which builds a comparative framework for capturing disease dynamics using high-dimensional, short time-series data. We demonstrate the utility of TimeAx by studying disease progression dynamics for multiple diseases and data types. Notably, for urothelial bladder cancer tumorigenesis, we identify a stromal pro-invasion point on the disease progression axis, characterized by massive immune cell infiltration to the tumor microenvironment and increased mortality. Moreover, the continuous TimeAx model differentiates between early and late tumors within the same tumor subtype, uncovering molecular transitions and potential targetable pathways. Overall, we present a powerful approach for studying disease progression dynamics—providing improved molecular interpretability and clinical benefits for patient stratification and outcome prediction.
Early selection of task-relevant features through population gating
Authors: Barbosa Joao , Proville Rémi , Rodgers Chris C. , DeWeese Michael R. , Ostojic Srdjan , Boubenec Yves 
Published: October 2023

AbstractBrains can gracefully weed out irrelevant stimuli to guide behavior. This feat is believed to rely on a progressive selection of task-relevant stimuli across the cortical hierarchy, but the specific across-area interactions enabling stimulus selection are still unclear. Here, we propose that population gating, occurring within primary auditory cortex (A1) but controlled by top-down inputs from prelimbic region of medial prefrontal cortex (mPFC), can support across-area stimulus selection. Examining single-unit activity recorded while rats performed an auditory context-dependent task, we found that A1 encoded relevant and irrelevant stimuli along a common dimension of its neural space. Yet, the relevant stimulus encoding was enhanced along an extra dimension. In turn, mPFC encoded only the stimulus relevant to the ongoing context. To identify candidate mechanisms for stimulus selection within A1, we reverse-engineered low-rank RNNs trained on a similar task. Our analyses predicted that two context-modulated neural populations gated their preferred stimulus in opposite contexts, which we confirmed in further analyses of A1. Finally, we show in a two-region RNN how population gating within A1 could be controlled by top-down inputs from PFC, enabling flexible across-area communication despite fixed inter-areal connectivity.
Polarization-driven reversible actuation in a photo-responsive polymer composite
Authors: Urban David , Marcucci Niccolò , Wölfle Christoph Hubertus , Torgersen Jan , Hjelme Dag Roar , Descrovi Emiliano 
Published: October 2023

AbstractLight-responsive polymers and especially amorphous azopolymers with intrinsic anisotropic and polarization-dependent deformation photo-response hold great promises for remotely controlled, tunable devices. However, dynamic control requires reversibility characteristics far beyond what is currently obtainable via plastic deformation of such polymers. Here, we embed azopolymer microparticles in a rubbery elastic matrix at high density. In the resulting composite, cumulative deformations are replaced by reversible shape switching – with two reversible degrees of freedom defined uniquely by the writing beam polarization. We quantify the locally induced strains, including small creeping losses, directly by means of a deformation tracking algorithm acting on microscope images of planar substrates. Further, we introduce free-standing 3D actuators able to smoothly undergo multiple configurational changes, including twisting, roll-in, grabbing-like actuation, and even continuous, pivot-less shape rotation, all dictated by a single wavelength laser beam with controlled polarization.
N-hydroxypipecolic acid triggers systemic acquired resistance through extracellular NAD(P)
Authors: Li Qi , Zhou Mingxi , Chhajed Shweta , Yu Fahong , Chen Sixue , Zhang Yanping , Mou Zhonglin 
Published: October 2023

AbstractSystemic acquired resistance (SAR) is a long-lasting broad-spectrum plant defense mechanism induced in distal systemic tissues by mobile signals generated at the primary infection site. Despite the discoveries of multiple potential mobile signals, how these signals cooperate to trigger downstream SAR signaling is unknown. Here, we show that endogenous extracellular nicotinamide adenine dinucleotide (phosphate) [eNAD(P)] accumulates systemically upon pathogen infection and that both eNAD(P) and the lectin receptor kinase (LecRK), LecRK-VI.2, are required in systemic tissues for the establishment of SAR. Moreover, putative mobile signals, e.g., N-hydroxypipecolic acid (NHP), trigger de novo systemic eNAD(P) accumulation largely through the respiratory burst oxidase homolog RBOHF-produced reactive oxygen species (ROS). Importantly, NHP-induced systemic immunity mainly depends on ROS, eNAD(P), LecRK-VI.2, and BAK1, indicating that NHP induces SAR primarily through the ROS-eNAD(P)-LecRK-VI.2/BAK1 signaling pathway. Our results suggest that mobile signals converge on eNAD(P) in systemic tissues to trigger SAR through LecRK-VI.2.
Polarization structured light 3D depth image sensor for scenes with reflective surfaces
Authors: Huang Xuanlun , Wu Chenyang , Xu Xiaolan , Wang Baishun , Zhang Sui , Shen Chihchiang , Yu Chiennan , Wang Jiaxing , Chi Nan , Yu Shaohua , Chang-Hasnain Connie J. 
Published: October 2023

AbstractHighly reflective surfaces are notorious in the field of depth sensing and three-dimensional (3D) imaging because they can cause severe errors in perception of the depth. Despite recent progress in addressing this challenge, there are still no robust and error-free solutions. Here, we devise a polarization structured light 3D sensor for solving these problems, in which high-contrast-grating (HCG) vertical-cavity surface-emitting lasers (VCSELs) are used to exploit the polarization property. We demonstrate accurate depth measurements of the reflective surfaces and objects behind them in various imaging situations. In addition, the absolute error and effective measurement range are measured to prove the applicability for a wide range of 3D applications. Our work innovatively combines polarization and depth information, opening the way for fully understanding and applying polarization properties in the 3D domain.