bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient state representation with artificial potential fields for reinforcement learning
Authors: Jiang Hao , Li Shengze , Zhang Jieyuan , Zhu Yuqi , Xu Xinhai , Liu Donghong
Published: February 2023

In the complex tasks environment, efficient state feature learning is a key factor to improve the performance of the agent’s policy. When encountering a similar new environment, reinforcement learning agents usually need to learn from scratch. However, humans naturally have a common sense of the environment and are able to use prior knowledge to extract environmental state features. Although the prior knowledge may not be fully applicable to the new environment, it is able to speed up the learning process of the state feature. Taking this inspiration, we propose an artificial potential field-based reinforcement learning (APF-RL) method. The method consists of an artificial potential field state feature abstractor (APF-SA) and an artificial potential field intrinsic reward model (APF-IR). The APF-SA can introduce human knowledge to accelerate the learning process of the state feature. The APF-IR can generate an intrinsic reward to reduce the invalid exploration and guide the learning of the agent’s policy. We conduct experiments on PySC2 with different mini-games. The experimental results show that the APF-RL method achieves improvement in the learning efficiency compared to the benchmarks.
Occurrence and distribution of pineapple mealybug wilt-associated viruses (PMWaVs) in MD2 pineapple fields in the Valle del Cauca Department, Colombia
Authors: Moreno Isabel , Rodríguez-Arévalo Kevin Alejandro , Tarazona-Velásquez Rubilma , Kondo Takumasa
Published: February 2023

MD2 pineapple production in the Valle del Cauca Department, Colombia, has increased in recent years due to its preference in the national and international markets. Pineapple mealybug wilt (PMW), reported in all production areas around the world, is associated with two mealybug species, Dysmicoccus brevipes and D. neobrevipes, and a group of virus species known as pineapple mealybug wilt-associated viruses (PMWaVs). In a previous study, D. brevipes was determined to be the main mealybug species associated with pineapples in the region; hence, the objective of this study was to determine the occurrence and distribution of PMWaVs in pineapple plants and specimens of D. brevipes collected in five MD2 pineapple fields in the Department of Valle del Cauca. Our results confirmed the presence of three virus species in both plant and mealybug specimens. PMWaV3 showed the highest detection frequencies (92.6% and 88.7%), followed by PMWaV1 (26.5% and 8.3%) and PMWaV2 (12.0% and 2.0%) in plant and mealybug samples, respectively. Mixed infections of PMWaVs were found also in the studied plant material. The most common virus association consisting of PMWaV1 and PMWaV3 was found in 30 plant samples (20%). The correlation analysis between each virus species found in mealybugs and their pineapple host suggests that PMWaV3 is not only transmitted through infested plant material, but that D. brevipes may also play a role in the dynamics of disease dissemination. The results of this study contribute to the understanding of PMWaV transmission in MD2 pineapple-cultivated areas in the Valle del Cauca region.
Argumentation in Complex Communication
Authors: Lewiński Marcin , Aakhus Mark
Published: February 2023

A pervasive aspect of human communication and sociality is argumentation: the practice of making and criticizing reasons in the context of doubt and disagreement. Argumentation underpins and shapes the decision-making, problem-solving, and conflict management which are fundamental to human relationships. However, argumentation is predominantly conceptualized as two parties arguing pro and con positions with each other in one place. This dyadic bias undermines the capacity to engage argumentation in complex communication in contemporary, digital society. This book offers an ambitious alternative course of inquiry for the analysis, evaluation, and design of argumentation as polylogue: various actors arguing over many positions across multiple places. Taking up key aspects of the twentieth-century revival of argumentation as a communicative, situated practice, the polylogue framework engages a wider range of discourses, messages, interactions, technologies, and institutions necessary for adequately engaging the contemporary entanglement of argumentation and complex communication in human activities.
The Nazi Past in Contemporary German Film
Authors: Bangert Axel
Published: February 2023

From intimate portrayals of ordinary Germans and Nazi leaders to immersive spectacles of war and defeat, this study argues that, since 1990, German film has focused on portraying the Nazi past from within.
Dynamical properties of minimal Ferenczi subshifts
Authors: ARBULÚ FELIPE , DURAND FABIEN
Published: February 2023

We provide an explicit
$\mathcal {S}$
-adic representation of rank-one subshifts with bounded spacers and call the subshifts obtained in this way ‘minimal Ferenczi subshifts’. We aim to show that this approach is very convenient to study the dynamical behavior of rank-one systems. For instance, we compute their topological rank, the strong and the weak orbit equivalence class. We observe that they have an induced system that is a Toeplitz subshift having discrete spectrum. We also characterize continuous and non-continuous eigenvalues of minimal Ferenczi subshifts.
Applying a distributed mass-balance model to identify uncertainties in glaciological mass balance on Brewster Glacier, New Zealand
Authors: Abrahim Bibi Nariefa , Cullen Nicolas James , Conway Jonathan Paul , Sirguey Pascal
Published: February 2023

A distributed mass-balance model is used over a 10-year period for the re-analysis of a glaciological mass-balance time series obtained from Brewster Glacier, New Zealand. Mass-balance modelling reveals glaciological mass balance has been overestimated, with an average mass loss of −516 mm w.e. a−1 not captured by observations at the end of the ablation season, which represents 35% of the annual mass balance. While the average length of the accumulation season (199 days) remains longer than the ablation season (166 days), melting is not uncommon in the core part of the accumulation season, with 2–32% of total snowfall being melted. Refreezing of meltwater is also important, with 10% of surface and subsurface melt being refrozen in the present climate. Net radiation, driven primarily by net shortwave radiation, is the main contributor to melt energy, with melt variability mainly influenced by the turbulent heat fluxes, net longwave radiation and the heat flux from precipitation in the ablation season. Snowfalls in summer are an important moderator of melt, highlighting the critical role of the ice-albedo feedback and phase of precipitation on seasonal mass balance. A complete homogenisation of the long-term glaciological mass balance for Brewster Glacier is still required.
A CATEGORIFICATION OF ACYCLIC PRINCIPAL COEFFICIENT CLUSTER ALGEBRAS
Authors: PRESSLAND MATTHEW
Published: February 2023

In earlier work, the author introduced a method for constructing a Frobenius categorification of a cluster algebra with frozen variables by starting from the data of an internally Calabi–Yau algebra, which becomes the endomorphism algebra of a cluster-tilting object in the resulting category. In this paper, we construct appropriate internally Calabi–Yau algebras for cluster algebras with polarized principal coefficients (which differ from those with principal coefficients by the addition of more frozen variables) and obtain Frobenius categorifications in the acyclic case. Via partial stabilization, we then define extriangulated categories, in the sense of Nakaoka and Palu, categorifying acyclic principal coefficient cluster algebras, for which Frobenius categorifications do not exist in general. Many of the intermediate results used to obtain these categorifications remain valid without the acyclicity assumption, as we will indicate, and are interesting in their own right. Most notably, we provide a Frobenius version of Van den Bergh’s result that the Ginzburg dg-algebra of a quiver with potential is bimodule
$3$
-Calabi–Yau.
Modelling 2D separation from a high lift
aerofoil with a non-linear eddy-viscosity model and
second-moment closure
Authors: Lien F. S. , Leschziner M. A.
Published: February 2023

A computational study is presented, which examines the
performance of variants of second-moment closure and
non-linear eddy-viscosity models when used to
predict attached and separated flows over a high
lift aerofoil for a range of incidence angles. The
capabilities of both model types, especially in
respect of resolving the onset of suction-side
separation at high incidence, are contrasted with
those of a low-Re k-ε model based
on the linear Boussinesq stress-strain relationship.
The second-moment model contains a conventional
linear approximation of the pressure straining
process; a cubic (realisable) variant has been
investigated in an earlier study and found to offer
no advantages. The quadratic eddy-viscosity model
features coefficients which are sensitised to the
strain and vorticity invariants. While both models,
in the form originally proposed, are superior to the
linear eddy-viscosity variant, neither performs well
in respect of resolving separation, unless modified
so as to return the requisite low level of shear
stress in the boundary layer approaching separation.
Once separation is resolved with sufficient realism,
the near wake aft of the trailing edge is also well
represented. All models return poor representations
of the far wake which is characterised by low levels
of turbulence production to dissipation ratio.
A three-dimensional moving mesh method for
the calculation of unsteady transonic
flows
Authors: Gaitonde A. L. , S. P. Fiddes
Published: February 2023

A three-dimensional moving mesh method for solving the
Euler equations describing the compressible flow
about a wing undergoing arbitrary motions and
deformations is described. A finite-volume
formulation is chosen where the volumes distort as
the wing moves or deforms. By using transfinite
interpolation, a technique for generating the
required sequence of grids has been developed.
Furthermore, as the speeds of the grid at the
vertices of the finite volumes are required by the
flow solver, transfinite interpolation is also used
to obtain these by interpolation of the boundary
speeds. A two-dimensional version of the method has
also been developed and results for both two- and
three-dimensional transonic flows are presented and
compared with experimental data where available.
Scramjet thrust measurement in a shock
tunnel
Authors: Paull A. , Stalker R. J. , Mee D. J.
Published: February 2023

This note reports tests in a shock tunnel in which a
fully integrated scramjet configuration produced net
thrust. The experiments not only showed that impulse
facilities can be used for assessing thrust
performance, but also were a demonstration of the
application of a new technique(1) to the
measurement of thrust on scramjet configurations in
shock tunnels. These two developments are of
significance because scramjets are expected to
operate at speeds well in excess of 2 km/s, and
shock tunnels offer a means of generating high Mach
number flows at such speeds.
On the effect of a strake-like junction
fillet on the lift and drag of a
wing
Authors: Bernstein L. , Hamid S.
Published: February 2023

An experimental study of the effects on the low-speed
aerodynamic characteristics of a strake-like fillet
is described, modelled on one used on an Airbus A320
variant fitted at the leading edge of a swept
wing-plate junction. The wing, swept back at 20°,
was of NACA 0015 section and chord 500 mm, both
normal to its leading edge. A turbulent boundary
layer had developed on the plate well ahead of the
junction. The tests were conducted at a unit
Reynolds number of 1.56 x 106
m-1.

Surface pressure distributions were measured on the
plate in the neighbourhood of the leading edge
junction and also on the aerofoil and fillet at wing
incidences of 0°, 3°, 6°, 9° and 12°. These were
supplemented by surface oil-flow studies.

The mean velocity and turbulence intensity fields
around the leading edge were examined for incidences
of 0° and 9°, using both a single tube yaw meter
developed for the purpose and an X-wire anemometer.
The X-wire anemometer was also used downstream of
the trailing edge of the swept wing; five of the
Reynolds stresses and the mean velocity field were
measured.

The sectional lift coefficients on the aerofoil were
found to diminish as the junction was approached,
slightly more so with the fillet than without it.
The sectional drag coefficients due to pressure
increased as the junction was approached, the fillet
moderating this increase to only a small extent.

However, the addition of the drooped fillet modified
the flow considerably. The horseshoe-like vortex was
less well defined than without it. At zero
incidence, the peak in the turbulence intensity
levels was virtually eliminated on what became
effectively the compression side of the wing due to
the local camber introduced by the asymmetric
fillet. The turbulence levels were also reduced by
the addition of the fillet at an incidence of 9°.
However, the turbulent activity was spread through a
larger proportion of the viscous region. The
secondary flows and the turbulence activity in the
wake are associated with unrecoverable kinetic
energy and will be manifest as drag on the surfaces
forming the junction.

It is concluded that a carefully designed fillet,
optimised for the cruise incidence of an aircraft,
can reduce the peak turbulence levels in the
junction. It remains unclear whether the total drag
associated with the junction flow can be reduced
significantly.

However because of its effects on the turbulence, there
may be other benefits, for example on the efficiency
of downstream elements, such as fuselage-mounted
engine intakes or the following stages of an axial
flow machine. Junction fillets might also be used to
control the scouring of river beds around bridge
piers.
Oct-tree terrain modelling methods for
terrain reference navigation systems
Authors: Allerton D. J. , M. C. Gia
Published: February 2023

This paper describes the use of oct-trees to represent
digitised terrain elevation data (DTED) in terrain
reference navigation (TRN) systems. Oct-trees
provide a regular method to represent digitised
terrain data where the level of detail of the
terrain is encoded in the tree structure. The use of
oct-trees also provides a basis for a significant
reduction in the on-line storage requirement for
DT-EDs. A method of encoding using Morton ordering
is introduced which allows DTEDs to be accessed as
oct-trees and quad-trees where the tree structures
are represented as pointerless structures.
Algorithms to construct and access terrain oct-trees
are presented which form a set of access primitives
for tree operations required in TRN applications.
The paper concludes with examples to illustrate the
efficiency of the methods described in the paper for
two DTEDs, in terms of performance of the tree
access operations and reductions in storage.
Research into the factors influencing
survival in aircraft accidents
Authors: Muir H. C.
Published: February 2023

The factors influencing survival in aircraft accidents
can be classified into configurational,
environmental, procedural or behavioural. New
methodologies which have been developed in order to
simulate emergency behaviour are introduced. A
series of experimental programmes in which the new
behavioural techniques are applied to
configurational, environmental and procedural
changes in the cabin are described. The results
suggest that the techniques provide the behavioural
and statistical data required for the assessment of
design options or safety procedures for use in
aircraft emergencies.
The verification of a theoretical
helicopter rotor blade sailing method by means of
windtunnel testing
Authors: Newman S. J.
Published: February 2023

The performance of a helicopter rotor has always been
dogged by the dissymmetry of air velocity over the
blades caused by its translation in a direction
substantially parallel to the plane of the rotor
disc. Furthermore, in order to make the rotor even
usable, this dissymmetry of lift has caused the
introduction of major mechanical complications to
the rotor hub. In forward flight the rotor is
aerodynamically split into two halves either side of
the flight direction. The advancing side, where the
rotor rotation is in the same sense as the forward
velocity, will see a greater dynamic head than the
retreating side, where the rotor rotation and
forward speed are in opposition. A rigid rotor would
consequently suffer a major rolling moment and if a
viable proposition is to be achieved the rolling
moment must be avoided.
Central-difference and upwind-biased
schemes for steady and unsteady Euler aerofoil
computations
Authors: Allen C. B.
Published: February 2023

Two numerical methods are presented for the computation
of steady and unsteady Euler flows. These are
applied to steady and unsteady flows about the NACA
0012 aerofoil, using structured grids generated by
the transfinite interpolation technique. An explicit
central-difference scheme is produced based on the
cell-vertex method of Ni modified by Hall. The
method is second-order accurate in time and space,
and with flow quantities stored at boundaries the
boundary conditions are simple to apply. This is a
definite advantage over the cell-centred approach of
Jameson, where extrapolation of the flow quantities
is required at the boundaries, making unsteady
boundary conditions difficult to apply. An explicit
upwind-biased scheme is also produced, based on the
flux-vector splitting of van Leer. The method adopts
a three stage Runge-Kutta time-stepping scheme and a
high-order spatial discretisation which is formally
third-order accurate for one-dimensional
calculations. The upwind scheme is shown to be
slightly more accurate than the central-difference
scheme for steady aerofoil flows, but it is not
clear which is the more accurate for unsteady
aerofoil flows. However, the central-difference
scheme requires less than half the CPU time of the
upwind-difference scheme, and hence is attractive,
especially when considering three-dimensional flows.
The transfinite interpolation technique is ideal for
generating moving structured grids due to its
simplicity, and grid speeds are available
algebraically by the same interpolation as grid
points. The method is also ideal for use in a
multi-block approach.
Preliminary results from a particle image
velocimetry study of blade–vortex
interaction
Authors: Horner M. B. , Stewart J. N. , Galbraith R. A. McD. , Grant I. , Coton F. N. , Smith G. H.
Published: February 2023

The results of a blade-vortex interaction (BVI) study
incorporating particle image velocimetry (PIV) are
presented. Test cases encompass a variety of
intersection geometries, including head-on parallel
interactions. Results provide quantified flow
visualisation images of the flows generated near the
blade tip and inboard during interactions. PIV
results are examined in the light of understanding
gained from previous pressure measurements made from
the same BVI facility. Both the difficulties and the
advantages of utilising the PIV technique in this
application are discussed.
Optimum design of composite stiffened wing
panels — a parametric study
Authors: Butler R.
Published: February 2023

The program VICONOPT is used to find the optimum (least
mass) dimensions of a range of stiffened wing panels
which are subject to buckling and material strength
constraints and are loaded in axial compression with
a sinusoidal manufacturing imperfection. Design
plots are presented to show the effects that various
rib spacings and stiffener types have on optimum
design mass. A simplified model of a complete wing
box is used to illustrate the design of a full wing
panel and plots of optimum values of design
variables at various stations along the wing have
been obtained. The results were chosen to illustrate
the practicality of optimisation with reference to
manufacture of a full wing panel and to show the
effect of changing the sophistication of modelling
and theory used for the range of panels considered.
The important aspects of the choice of design
variables and design concepts are highlighted and
percentage savings in mass, compared with an optimum
metal panel design, are given for the various
(global) optima found along with some examples of
(rejected) local optima.
On the induced drag reduction due to
propeller-wing interaction
Authors: Chiocchia G. , Pignataro S.
Published: February 2023

The aerodynamic interaction between a wing and a couple
of propellers in tractor configuration is
investigated by means of a model based on the
lifting line concept and under the assumption of
quasi-steady incompressible motion of inviscid
fluid. The ways the propellers influence the wing
performances, particularly the induced drag, are
analysed. It turns out that the lift increase and
the possible drag reduction depend strongly on the
direction of the blade rotation and on the propeller
distances from midspan, and result from two main
effects: the direct propeller induction on the wing
and the modification of the lift distribution along
the span. An additional nonlinear (mixed)
contribution affects the drag but has only
negligible influence on the lift. The described
model allows one to evaluate separately all these
effects and helps understanding their influence on
the global modification of the wing
performances.
A note on the pressure drag of a
forward-swept-wing-plate junction
Authors: Arnott A. D. , Bernstein L. , Petty D. G.
Published: February 2023

The forces due to normal pressure have been measured in
the region of the junction between a rear-loaded
wing swept forward at 28°, and a flat plate on which
a turbulent boundary layer had developed. The
Reynolds number was 1·03 × 106, based on
the streamwise wing-chord of 500 mm. At low
incidences, 0° < α ≤ 6°, the
local pressure drag coefficients were found to be
negativeaway from the junction,
and the interaction with the junction was found to
be favourable;that is the pressure
drag coefficient became more negative as the
junction was approached. At α = −3° the pressure
drag coefficient changed from a positive value away
from the junction to a negative value close to the
plate. These results contrast with those for a
swept-back wing-plate interaction, which has been
reported as being unfavourable so far as the
pressure drag was concerned. At 6° incidence, the
interaction remained favourable but there was
evidence of root stall beginning. At an incidence of
9°, root stall was much more marked and the positive
pressure drag coefficient increased as the junction
was approached.
A study of wall jets resulting from single
and multiple inclined jet
impingement
Authors: Miller P.
Published: February 2023

An experimental investigation into the wall jets
created by a single inclined, twin inclined and a
four inclined jet impingement arrangement is
described. Wall jet velocity profiles were recorded
at various azimuthal and radial locations for a
range of nozzle heights at jet pressures
representative of current V/Stol technology. Use was
made of wall jet properties established for a normal
jet impingement to provide a means of comparing the
attributes of the various configurations.
Non-splayed twin inclined impinging jets generate
symmetry plane reinforcement and weakening in
regions remote from the interaction. Splayed jet
geometries show significant height effects on ground
plane flow development. The four-jet configuration
also demonstrates velocity reinforcement at the
lines of wall jet interaction, together with a
weakening of the flows remote from the interaction
planes. Reinforcement velocities for the four-jet
case are significantly lower than those expected
from the constituent twin-jet flows.
Hypersonic control flap
effectiveness
Authors: Kumar D. , Stollery J. L.
Published: February 2023

The effects of flap deflection, configuration incidence
and leading edge bluntness on boundary layer
separation and transition have been studied
experimentally. A quasi two-dimensional flat plate
equipped with a full span trailing edge control flap
has been employed for these tests.

The studies have been carried out in a hypersonic gun
tunnel at M∞ = 8·2 and Re∞/cm
= 9·0 × 104. The flap deflection angles
studied were in the range 0° ≤ β ≤ 30°. The
incidence range was from zero to α = 10° (positive α
is nose down). Leading edge bluntness effects were
simulated by the introduction of a hemi-cylindrical
leading edge.

The flow structure was studied using high speed
Schlieren photography as well as surface pressure
and heat transfer measurements. Liquid crystals were
employed to study the threedimensionality of the
flow structure for selected configurations.
Analytical theories have been developed to estimate
the flap pressure and heat transfer levels for the
sharp and blunt configurations. These are compared
against experimental measurements.
Future rotorcraft technology
developments
Authors: Tyler D. J. , Vincent A. H.
Published: February 2023

The rotorcraft has evolved considerably since the
introduction of the first helicopters into civil and
military service in the early post-war years. The
latest generation of rotorcraft now entering
production make use of sophisticated technologies
and set new standards for performance, productivity
and safety. The paper discusses the current state of
rotorcraft technology and outlines potential
improvements for the future.

As a prelude to the discussion of technology
improvements, future market conditions and drivers
are examined. Cost is highlighted as a major
preoccupation for civil and military operators and
cost-effectiveness and operational flexibility are
noted as the key market requirements for the
future.

A range of platform and system issues are reviewed and
potential improvements discussed. Areas covered
include

•

rotor
systems

•

powerplant

•

transmission

•

fuselage
structures

•

vibration
reduction

•

flight
controls

•

human
machine
interface

•

mission
systems.

The potential for new rotorcraft configurations is
considered with particular attention given to the
evolutionary step of thrust and lift compounding,
which offers a wider flight envelope for rotorcraft
without the high cost of radical configuration
change.

Finally, the need for an integrated approach to the
rotorcraft design and development process is
emphasised. The highly capable tools and techniques
that are now becoming available are considered vital
to future process improvements. It is foreseen that
increased resources will be needed during the early
stages of product development in order to produce
first time designs that meet market requirements.
The importance of technology demonstration as a
means of providing technology maturity is discussed.
It is concluded that demonstration programmes will
need to be closely linked to market requirements in
the future with costs shared between all sections of
the rotorcraft community.
On innovation in
aerodynamics
Authors: Hall M. G.
Published: February 2023

A discussion is presented of innovative change in
aerodynamics, in which the transformation of
practical transonic aerodynamics by computational
fluid dynamics is taken as a case study for the
lessons to be learnt. The study focuses on the
historic breakthroughs of Emmons and Murman and Cole
in the calculation of transonic flows, and on the
exploitation of these at the Royal Aircraft
Establishment to provide industry with a new, and
highly successful, tool for practical transonic wing
design. It reaffirms the view that a first
prerequisite for innovation is the active presence
of individuals with clear vision and a spirit of
adventure. Further, innovative work will flourish
only if the climate is favourable, no matter how
exceptional the individuals may be. The discussion
concludes with remarks on opportunities for
innovation in the treatment of Shockwaves, turbulent
shear layers and complex practical
configurations.
FCS design for structural coupling
stability
Authors: Caldwell B. D.
Published: February 2023

ACT embodying FBW and digital computing is now
implemented routinely in almost all classes of
aircraft, and is often essential in achieving
performance requirements. However, careful design,
thorough understanding, and attention to detail are
necessary if the benefits of ACT are to be realised
and attention must be focused appropriately among
the issues to be resolved to ensure that development
proceeds efficiently and overall costs are
minimised. This paper introduces structural coupling
as one of the important “details” of FCS design, and
shows how the “state-of-the-art” has developed at
BAe Warton in order to help achieve the performance
specification for a modern weapons system, while
maintaining a balanced and efficient FCS design
effort.
An investigation of piloting strategies for
engine failures during takeoff from offshore
platforms
Authors: Thomson D. G. , Taylor C. D. , Talbot N. , Ablett R. , Bradley R.
Published: February 2023

An analysis technique capable of simulating the effect
of engine failure during takeoff from offshore
platforms is presented. Use is made of inverse
simulation whereby the control actions required for
a subject helicopter to follow a particular
trajectory can be established. A mathematical
representation of the towering takeoff procedure,
and details of the modified inverse simulation
technique needed to cope with the modelling of an
engine failure are described. Detailed piloting
accounts of the strategy used to fly the towering
takeoff (with and without engine failures) are also
given and are used to give qualitative validation of
the analytical approach. Simulation results for a
single engine failure of a transport helicopter
during critical phases of a towering takeoff are
presented. Finally, some directions for future work
and potential applications of the technique are
discussed.
At war? Party status and the war in Ukraine
Authors: Wentker Alexander
Published: February 2023

Military support to Ukraine has been accompanied by debates as to when Western states would find themselves ‘at war’ with Russia. This political and legal discourse reminds us that international law needs concepts to identify who is a party to an international armed conflict. Identifying parties is crucial because the international legal regulation of armed conflict remains, in many ways, structured by reference to party status – even if the legal meaning of being a party today differs significantly from the traditional implications of being ‘at war’. To capture the increasingly complex co-operation patterns of today’s and tomorrow’s wars, this article identifies the contours for a framework of legal criteria for establishing when a state has become a party to an ongoing international armed conflict. To become a party under this framework, a state must knowingly make a contribution to the conflict that is of a character such that it is directly connected to harm caused to the adversary. That contribution must be sufficiently closely co-ordinated with fellow parties to allow for involvement in the decision-making processes regarding co-ordinated military operations. Applying these criteria to key support scenarios, as exemplified in Russia’s war against Ukraine, permits reasonable distinctions, also with a view to future conflicts. More widely, the analysis of party status may enhance our understanding of the architecture of the international legal regulation of armed conflict as a whole, and its ability to respond to the realities of contemporary conflicts.
Mandatory human rights due diligence laws in Europe: A mirage for rightsholders?
Authors: Deva Surya
Published: February 2023

Mandatory human rights due diligence (HRDD) laws in the European Union (EU) – both enacted and in the making – seem to be a promising tool to harden soft international standards in the business and human rights (BHR) field, the most prominent of these being the UN Guiding Principles on Business and Human Rights (UNGPs). This article develops a two-layered critique of mandatory HRDD laws. It problematizes the very concept of HRDD as articulated by the UNGPs. I will argue that due to various conceptual, operational and structural limitations, HRDD alone will not bring the desired changes for rightsholders, because this process does not address various asymmetries of power between corporations and affected communities. The second layer of critique concerns the content of mandatory HRDD laws enacted in France, the Netherlands, Switzerland, Norway and Germany. Assessing these laws vis-à-vis six preconditions required to protect effectively people and the planet from business-related harms, it is clear that these mandatory HRDD laws are half-hearted attempts to tame business-related human rights abuses and hold the relevant corporate actors accountable. In addition to developing more ambitious mandatory HRDD laws in future, states should employ a range of additional regulatory tools that pay greater attention to achieving outcomes, drawing red lines in certain situations, and promoting access to remedy and corporate accountability.
How Jacob Zuma Revitalized Feminism in South Africa
Authors: Hassim Shireen
Published: February 2023

On August 6, 2016, the week of the South African public holiday Women’s Day, an extraordinary protest held the nation spellbound. Then president Jacob Zuma was announcing the results of local government elections live on national television when four young women walked out of the throng of election officials and politicians. They stood in front of the president, silent but visible on the televised screen. They held up placards: “I am 1 in 3,” “Ten Years Later,” “Khanga,” “Remember Khwezi.” Although the protesters stood for the duration of the broadcast, they were forcibly removed by security agents immediately after Zuma left the stage and the cameras moved offscreen. Hustled to the back of the room, they were lambasted by senior women leaders of the African National Congress (ANC) for their “inappropriate” action. This was a spectacular demonstration: silent and nonviolent, its tactics and timing pierced the performance of presidential authority and made visible a new form of feminism.
#JusticePourMirabelle: The Resurgence of a Transnational Cameroonian Feminist Movement
Authors: Ndengue Rose , Atsem Atsem , Maveun Maveun
Published: February 2023

For decades, African women have participated in the Black feminist struggle for women’s rights and racial, social, economic, and political justice (Collins 2017; Tamale 2020). In the 1950s, during the fight for independence across the continent, a radical and transnational feminist movement emerged with African women’s protests to “crack the norms of gender and colonial order” (Ndengue 2016) in both urban and rural postcolonial contexts (Falola and Paddock 2011; Mougoué 2019; Nchoji Nkwi 1985; Ndengue 2018). Protests have transnational effects (Johnson-Odim 2009; Terretta 2013). Today, transnationalism relies on social media platforms as sites of calls to action. They constitute alternative public spaces for expression and activism in constrained political environments (Ngono 2018) and platforms that facilitate informal transnational connections. These transnational connections are accompanied by explicit and assertive claims of feminism by a growing number of (young) women.
Conceptualizing the fiscal state: implications for sub-Saharan Africa
Authors: Jeppesen Matilde , Bak Ane Karoline , Kjær Anne Mette
Published: February 2023

This paper contributes to the debate on domestic revenue mobilization and state-building in the Global South by exploring the concept of fiscal states and the common assumption that such states are present in sub-Saharan Africa. We systematically review the diverse understandings of the fiscal state across relevant literatures to revisit its conceptualization. On that basis, we define the fiscal state as a state whose public revenue base is dominated by tax revenue and loans, and where the relationship between taxation and external and domestic borrowing is balanced and thereby sustainable and characterized by interdependence. We distinguish the fiscal state conceptually from the tax, debt, and rentier states and present a typology of these ideal state types, discussing illustrative empirical examples of different states in sub-Saharan Africa. These illustrate that not all sub-Saharan states can be categorized as fiscal states. This is important because when African states are regarded as fiscal states, assumptions are made about their economic structures; yet, to the extent that these are absent, fiscal policy reforms are unlikely to carry long-term positive effects.
Linking Ice‐Phase Microphysics to Raindrop Characteristics in Deep Convection: A Warm‐Sector Extreme Rainfall Case Study in Eastern China
Authors: Chen Gang , Zhao Kun , Wen Long , Yang Ji , Zheng Yuanyuan , Xu Fen , Lyu Fanchao , Sun Kangyuan , Sun Liangxiao
Published: February 2023

In this study, we examine the evolution of ice‐phase microphysics [polarimetric radar signatures and identified graupel and hail (GH) (hereafter, GH) distributions] and raindrop characteristics [drop size distribution (DSD) and rainfall intensity] in a warm‐sector extreme rainfall case during the Meiyu period in Eastern China. Deep convection is identified in this rainstorm, raindrop characteristics are found to be deeply affected by the GH distribution condition, heavy rainfall (rain rate >20 ) is basically contributed by convective samples with GH identified aloft. As GH height rises, number concentration and mean size of raindrops increase accordingly, leading to the growth of rainfall intensity. Extreme rainfall (rain rate >100 ) is majorly induced by deep convection with hail or widespread (over 10 km level) graupel, melting of the abundant highly‐rimed particles plays a dominant role in generating high concentration raindrops. By revealing the link between GH distribution conditions and raindrop characteristics, the study helps to understand the specific role of ice‐phase processes to the formation of low‐level raindrops in deep convection.
Understanding Models' Global Sea Surface Temperature Bias in Mean State: From CMIP5 to CMIP6
Authors: Zhang Qibei , Liu Bo , Li Shuanglin , Zhou Tianjun
Published: February 2023

This paper evaluates sea surface temperature (SST) biases of coupled models participating in Coupled Model Intercomparison Project Phase 5 (CMIP5) and CMIP6. Overall, CMIP6 models perform better than CMIP5 ones in reproducing SST climatology, with lower multi‐model ensemble mean (MME) globally averaged absolute bias (1.17 vs. 1.31 K). MME bias in global mean annual SST shifts from cooling (−0.09 ± 0.52 K) to warming (0.23 ± 0.60 K). Regionally, in CMIP6 cooling biases over the Northwest Pacific and North Atlantic are reduced by 20% and 18%, while warming biases over the Northeast Pacific, Southeast Atlantic and Southern Ocean are increased by 25%, 16% and 107% respectively. These changes are mainly attributed to the combined effects from aggravated positive (or alleviated negative) bias in clear‐sky surface downward longwave radiation, and alleviated negative bias in cloud radiative effect, partially reduced by enhanced cooling bias in clear‐sky surface downward shortwave radiation.
MMS Observations of Dayside Warm (Several eV to 100 eV) Ions in the Middle and Outer Magnetosphere
Authors: Goldstein J. , Burch J. L. , Fuselier S. A. , Gomez R. , Gonzalez C. A. , Kim M. J. , Mukherjee J. , Turner N. E. , Wilson M. E.
Published: February 2023

Warm (several eV to 100 eV) ions are an important, and still poorly understood, component of the magnetospheric plasma environment. We present the first comprehensive statistical analysis of several distinct populations of warm ions in the dayside middle and outer magnetosphere. We analyze 7 months (1 September 2015–31 March 2016) of Magnetospheric Multiscale Hot Plasma Composition Analyzer data comprising 734,200 moments (density, temperature) and energy‐dependent pitch angle distributions (PADs) of three major ion species (H+, He+, and O+) with energy ≤100 eV. PADs are represented by an energy‐averaged index that characterizes the shape of the PAD as field‐aligned (FA), pancake, or isotropic. We use filtering by temperature, pitch angle, and concentration to distinguish different populations, and obtain new and more complete information about average density, temperature, PADs, and composition. Our analysis explores two known populations of warm ions: the warm plasmasphere (WPS) and the warm cloak/trough (C/T). The WPS is a higher‐temperature, higher‐L extension of the duskside plasmaspheric bulge, containing mostly trapped (pancake/isotropic) ions with an H+:He+:O+ order of ion dominance. The C/T contains mostly FA warm ions with a dawnward (duskward) temperature gradient for H+ (He+ and O+), lower densities, and an H+:O+:He+ order of ion dominance. The WPS‐C/T overlap contains a mixture of the two populations (e.g., FA He+ in WPS, trapped O+ in C/T). Pancake (FA) PADs are correlated with higher (lower) density/temperature. Our analysis also identifies warm ions in the low‐energy plasma sheet. Our work consolidates and systematically extends the characterizations of warm ions reported in previous studies.
MPAS‐A Variable‐Resolution Simulations for Summer Monsoon Over China: Comparison Between Global and Regional Configuration
Authors: Cheng Yiyuan , Hui Pinhong , Liu Dongqing , Fang Juan , Wang Shuyu , Wang Shuguang , Tang Jianping
Published: February 2023

Driven by ERA‐Interim reanalysis, two climate simulations are conducted from April to August for 20 years (1998–2017) during the East Asia summer monsoon with Model for Prediction Across Scale‐Atmosphere (MPAS‐A). The global variable‐resolution (MPAS‐VR) and regional (MPAS‐RCM) configurations are adopted under the same model framework with 92–25 km mesh refinement centered over Mainland China (MPAS‐A experiments hereafter). MPAS‐VR allows flexible interactions across scales. Constrained by the “reanalysis‐based” lateral boundary conditions (LBCs), MPAS‐RCM could well capture the evolution of large‐scale fields and becomes a proper reference for evaluating MPAS‐VR. The evaluations are conducted for precipitation, near‐surface air temperature, and circulation features against observed climate. Two MPAS‐A experiments present comparable results for the mean climatology and interannual variability except that MPAS‐VR presents wet biases along the tropical ocean and underestimation in the Yangtze–Huaihe River basin. Compared with MPAS‐VR, MPAS‐RCM presents better daily variations and rain belts’ evolution, which demonstrates the crucial effects of the LBCs for the limited‐area model. The simulated circulation and moisture flux can explain most of the deviations. However, two MPAS‐A experiments show consistent results for the extreme precipitation frequency and the extreme indices over Mainland China. With the same dynamic core and model physics, those climate features are similarly resolved by the two simulations. Thus, the 92–25 km MPAS‐VR simulation is demonstrated as a promising tool for regional climate hindcast.
Dissolved Iron Concentration and the Solubility Inferred by Humic‐Like Fluorescent Dissolved Organic Matter in the Intermediate Water in the North Pacific Including the Marginal Seas
Authors: Yamashita Youhei , Nishioka Jun
Published: February 2023

The marginal seas have been found to be important external sources of dissolved iron (Fe) in the North Pacific through circulation of intermediate water. Here, we show comprehensive spatial distributions of dissolved Fe concentrations and Fe(III) solubilities inferred from humic‐like fluorescent dissolved organic matter (FDOMH) over the North Pacific, including the marginal seas, the Sea of Okhotsk, and the Bering Sea. FDOMH was used as a proxy of chemical speciation of dissolved Fe in the intermediate and deep waters where liner relationships were previously observed between FDOMH and Fe(III) solubility. When dissolved Fe concentration exceeds Fe(III) solubility, Fe(III) solubility is assumed to be equivalent to concentration of FDOMH‐Fe complexes, and excess dissolved Fe concentration above the Fe(III) solubility is assumed to be colloidal Fe which is not complexed with FDOMH. In the intermediate water, the dissolved Fe concentration exceeded the Fe(III) solubility in the marginal seas, while excess Fe(III) solubility was evident downstream of the intermediate water circulation, suggesting that the major dissolved Fe chemical form derived from shelf and slope sediments in the marginal seas changed from colloidal Fe to FDOMH‐Fe complexes. With the previous findings, namely the dominance of labile particulate Fe in total Fe in the intermediate water of the Sea of Okhotsk and the Bering Sea, we hypothesized that the average size of sediment‐derived Fe decreases during transportation by intermediate water, most likely due to reversible scavenging with the highest removal rate for labile particulate Fe and the lowest removal rate for FDOMH‐Fe complexes.
Human gene-engineered calreticulin mutant stem cells recapitulate MPN hallmarks and identify targetable vulnerabilities
Authors: Foßelteder Johannes , Pabst Gabriel , Sconocchia Tommaso , Schlacher Angelika , Auinger Lisa , Kashofer Karl , Beham-Schmid Christine , Trajanoski Slave , Waskow Claudia , Schöll Wolfgang , Sill Heinz , Zebisch Armin , Wölfler Albert , Thomas Daniel , Reinisch Andreas
Published: February 2023

Calreticulin (CALR) mutations present the main oncogenic drivers in JAK2 wildtype (WT) myeloproliferative neoplasms (MPN), including essential thrombocythemia and myelofibrosis, where mutant (MUT) CALR is increasingly recognized as a suitable mutation-specific drug target. However, our current understanding of its mechanism-of-action is derived from mouse models or immortalized cell lines, where cross-species differences, ectopic over-expression and lack of disease penetrance are hampering translational research. Here, we describe the first human gene-engineered model of CALR MUT MPN using a CRISPR/Cas9 and adeno-associated viral vector-mediated knock-in strategy in primary human hematopoietic stem and progenitor cells (HSPCs) to establish a reproducible and trackable phenotype in vitro and in xenografted mice. Our humanized model recapitulates many disease hallmarks: thrombopoietin-independent megakaryopoiesis, myeloid-lineage skewing, splenomegaly, bone marrow fibrosis, and expansion of megakaryocyte-primed CD41+ progenitors. Strikingly, introduction of CALR mutations enforced early reprogramming of human HSPCs and the induction of an endoplasmic reticulum stress response. The observed compensatory upregulation of chaperones revealed novel mutation-specific vulnerabilities with preferential sensitivity of CALR mutant cells to inhibition of the BiP chaperone and the proteasome. Overall, our humanized model improves purely murine models and provides a readily usable basis for testing of novel therapeutic strategies in a human setting.