bluuebunny/crossref_metadata_2025 huggingface dataset:
Health professionals’ practices and perspectives of post-stroke coordinated discharge planning: a national survey
Authors: Ingram Lara , Pitt Rachelle , Shrubsole Kirstine
Published: March 2024

Background It is best practice for stroke services to coordinate discharge care plans with primary/community care providers to ensure continuity of care. This study aimed to describe health professionals’ practices in stroke discharge planning within Australia and the factors influencing whether discharge planning is coordinated between hospital and primary/community care providers. Methods A mixed-methods survey informed by the Theoretical Domains Framework was distributed nationally to stroke health professionals regarding post-stroke discharge planning practices and factors influencing coordinated discharge planning (CDP). Data were analysed using descriptive statistics and content analysis. Results Data from 42 participants working in hospital-based services were analysed. Participants reported that post-stroke CDP did not consistently occur across care providers. Three themes relating to perceived CDP needs were identified: (1) a need to improve coordination between care providers, (2) service-specific management of the discharge process, and (3) addressing the needs of the stroke survivor and family. The main perceived barriers were the socio-political context and health professionals’ beliefs about capabilities. The main perceived facilitators were health professionals’ social/professional role and identity, knowledge, and intentions. The organisation domain was perceived as both a barrier and facilitator to CDP. Conclusion Australian health professionals working in hospital-based services believe that CDP promotes optimal outcomes for stroke survivors, but experience implementation challenges. Efforts made by organisations to ensure workplace culture and resources support the CDP process through policies and procedures may improve practice. Tailored implementation strategies need to be designed and tested to address identified barriers.
NADPH oxidase exerts a B cell–intrinsic contribution to lupus risk by modulating endosomal TLR signals
Authors: Liu Shuozhi , Lagos Jonathan , Shumlak Natali M. , Largent Andrea D. , Lewis Sebastien T.E. , Holder Ursula , Du Samuel W. , Liu Yifan , Hou Baidong , Acharya Mridu , Jackson Shaun W.
Published: March 2024

Genome-wide association studies in systemic lupus erythematosus (SLE) have linked loss-of-function mutations in phagocytic NADPH oxidase complex (NOX2) genes, including NCF1 and NCF2, to disease pathogenesis. The prevailing model holds that reduced NOX2 activity promotes SLE via defective efferocytosis, the immunologically silent clearance of apoptotic cells. Here, we describe a parallel B cell–intrinsic mechanism contributing to breaks in tolerance. In keeping with an important role for B cell Toll-like receptor (TLR) pathways in lupus pathogenesis, NOX2-deficient B cells exhibit enhanced signaling downstream of endosomal TLRs, increased humoral responses to nucleic acid-containing antigens, and the propensity toward humoral autoimmunity. Mechanistically, TLR-dependent NOX2 activation promotes LC3-mediated maturation of TLR-containing endosomes, resulting in signal termination. CRISPR-mediated disruption of NCF1 confirmed a direct role for NOX2 in regulating endosomal TLR signaling in primary human B cells. Together, these data highlight a new B cell–specific mechanism contributing to autoimmune risk in NCF1 and NCF2 variant carriers.
Macro-clusters: CD301b+ DCs prime Th2 responses
Authors: Abberger Hanna , Groom Joanna R.
Published: March 2024

In this issue of JEM, Lyons-Cohen et al. (https://doi.org/10.1084/jem.20231282) reveal that lymph node macro-clusters provide a spatial niche where CD301b+ cDC2s and CD4+ T cells interact. These integrin-mediated cellular hubs promote enhanced co-stimulation and cytokine signaling to drive Th2 differentiation.
A novel, patient-derived RyR1 mutation impairs muscle function and calcium homeostasis in mice
Authors: Benucci Sofia , Ruiz Alexis , Franchini Martina , Ruggiero Lucia , Zoppi Dario , Sitsapesan Rebecca , Lindsay Chris , Pelczar Pawel , Pietrangelo Laura , Protasi Feliciano , Treves Susan , Zorzato Francesco
Published: March 2024

RYR1 is the most commonly mutated gene associated with congenital myopathies, a group of early-onset neuromuscular conditions of variable severity. The functional effects of a number of dominant RYR1 mutations have been established; however, for recessive mutations, these effects may depend on multiple factors, such as the formation of a hypomorphic allele, or on whether they are homozygous or compound heterozygous. Here, we functionally characterize a new transgenic mouse model knocked-in for mutations identified in a severely affected child born preterm and presenting limited limb movement. The child carried the homozygous c.14928C>G RYR1 mutation, resulting in the p.F4976L substitution. In vivo and ex vivo assays revealed that homozygous mice fatigued sooner and their muscles generated significantly less force compared with their WT or heterozygous littermates. Electron microscopy, biochemical, and physiological analyses showed that muscles from RyR1 p.F4976L homozygous mice have the following properties: (1) contain fewer calcium release units and show areas of myofibrillar degeneration, (2) contain less RyR1 protein, (3) fibers show smaller electrically evoked calcium transients, and (4) their SR has smaller calcium stores. In addition, single-channel recordings indicate that RyR1 p.F4976L exhibits higher Po in the presence of 100 μM [Ca2+]. Our mouse model partly recapitulates the clinical picture of the homozygous human patient and provides significant insight into the functional impact of this mutation. These results will help understand the pathology of patients with similar RYR1 mutations.
An approximate application of quantum gravity to the rotation problem
Authors: Jones R Michael
Published: March 2024

Arbitrary initial conditions allow solutions of Einstein’s field equations for General Relativity to have arbitrarily large relative rotation of matter and inertial frames. The ‘Rotation Problem’ is to explain why the measured relative rotation rate is so small. As it turns out, nearly any reasonable theory of quantum gravity can solve the rotation problem by phase interference. Even as early as about a quarter of a second after the initial simgularity, quantum cosmology would limit the cosmologies that contribute significantly to a path integral calculation to have relative rms rotation rates less than about 10−51 radians per year. Those calculations are based on using 50 e-foldings during inflation. For 55 or 60 e-foldings, the cosmologies contributing significantly to the path integral would have even smaller relative rotation rates. In addition, although inflation dominates the calculation, even if there had been no inflation, the cosmologies contributing significantly to the path integral would have relative rotation rates less than about 10−32 radians per year at about a quarter of a second after the initial singularity. These calculations are insensitive to the details of the theory of quantum gravity because the main factor depends only on the size of the visible Universe, the Planck time, the free-space speed of light, the Hubble parameter, and the number of e-foldings during inflation. These calculations use the Einstein–Hilbert action in quantum gravity, including large-scale relative rotation of inertial frames and the matter distribution, in which each ‘path’ is a cosmology with a different rms relative rotation rate. The calculations include inflation for 50, 55, and 60 e-foldings, and for values of the dependence of relative rotation rate on cosmological scale factor a as a
−m
for various values of m. The calculation shows that the action is an extremum at zero rms relative rotation rate.
Uniqueness results for inverse source problems for semilinear elliptic equations
Authors: Liimatainen Tony , Lin Yi-Hsuan
Published: March 2024

We study inverse source problems associated to semilinear elliptic equations of the form

Δ
u

x

+
a

x
,
u

=
F

x

on a bounded domain

Ω
⊂

R

n

,

n
⩾
2

. We show that it is possible to use nonlinearity to recover both the source F and the nonlinearity

a
(
x
,
u
)

simultaneously and uniquely for a class of nonlinearities. This is in contrast to inverse source problems for linear equations, which always have a natural (gauge) symmetry that obstructs the unique recovery of the source. The class of nonlinearities for which we can uniquely recover the source and nonlinearity, includes a class of polynomials, which we characterize, and exponential nonlinearities.

For general nonlinearities

a
(
x
,
u
)

, we recover the source F(x) and the Taylor coefficients

∂
u
k

a
(
x
,
u
)

up to a gauge symmetry. We recover general polynomial nonlinearities up to the gauge symmetry. Our results also generalize results of Feizmohammadi and Oksanen (2020 J. Differ. Equ.
269 4683–719), Lassas et al (2020 Rev. Mat. Iberoam.
37 1553–80) by removing the assumption that

u
≡
0

is a solution. To prove our results, we consider linearizations around possibly large solutions.

Our results can lead to new practical applications, because we show that many practical models do not have the obstruction for unique recovery that has restricted the applicability of inverse source problems for linear models.
Consistency of the Bayes method for the inverse scattering problem
Authors: Furuya Takashi , Kow Pu-Zhao , Wang Jenn-Nan
Published: March 2024

In this work, we consider the inverse scattering problem of determining an unknown refractive index from the far-field measurements using the nonparametric Bayesian approach. We use a collection of large ‘samples’, which are noisy discrete measurements taking from the scattering amplitude. We will study the frequentist property of the posterior distribution as the sample size tends to infinity. Our aim is to establish the consistency of the posterior distribution with an explicit contraction rate in terms of the sample size. We will consider two different priors on the space of parameters. The proof relies on the stability estimates of the forward and inverse problems. Due to the ill-posedness of the inverse scattering problem, the contraction rate is of a logarithmic type. We also show that such contraction rate is optimal in the statistical minimax sense.
Installation angle calibration between the star sensor and gyro unit using the equivalent rotation vector transformation
Authors: Ma Liheng , Li Qiyao , Chen Yanfeng , Luo Xiao , Kai Li , Zhang Su
Published: March 2024

To improve the dynamic performance of the star sensor, different star image frames are correlated using the attitude-correlated frame (ACF) approach, and the attitude changes among these star image frames are measured by the strapdown gyro unit (GU). The GU consists of three orthogonally assembled gyros, while the accelerometer is excluded. Accurate calibration of the installation angles between the star sensor and the GU is essential for the ACF approach. An installation angle calibration method using the equivalent rotation vector transformation between the star sensor and the GU is proposed in this work. Through three to five maneuverings of the star sensor/GU system, the equivalent rotation vector transformation of the observed vector is performed by the installation matrix, and the optimal values of the installation angles are estimated. Simulations and experiments are designed and conducted, and both verify the proposed calibration method. The calibration results in the experiment show that the standard deviation of the installation angles in each measurement data group is less than 5 arcseconds and the difference between different data sets is less than 14 arcseconds, both for the three axes, which are accurate enough for the ACF approach and other applications.
Rolling bearing fault diagnosis based on the fusion of sparse filtering and discriminative domain adaptation method under multi-channel data-driven
Authors: Jiao Zonghao , Zhang Zhongwei , Li Youjia , Wu Yuting , Liu Lu , Shao Sujuan
Published: March 2024

Currently, the diagnostic performance of many deep learning algorithms may drop dramatically when the distribution of training data is significantly different from that of the test data. Moreover, the fault diagnosis approaches based on single-channel data may suffer problems such as large precision fluctuation, low reliability, and incomplete expression of fault features. To overcome the above deficiencies, a novel multi-channel data-driven fault recognition method based on the fusion of sparse filtering (SF) and discriminative domain adaptation (MSFDDA) is proposed in this article. Firstly, inspired by attention mechanisms and information fusion methods, a spectrum-based weighted multi-channel data fusion strategy is designed to fully utilize the data collected by sensors to obtain a more comprehensive representation of fault features. Then, the joint probability-based discriminative maximum mean discrepancy algorithm is introduced into the SF method to strengthen the capability of extracting the domain invariant features. Finally, two bearing datasets are employed to verify the validity of the MSFDDA method, which proved to be superior to other current domain adaptation methods.
Statistical analysis of magnetic divertor configuration influence on H-mode transitions
Authors: Andrew Y , Dunsmore J , Ashton-Key T , Farre Kaga H , Kim E , Rhodes T L , Schmitz L , Yan Z
Published: March 2024

DIII-D plasmas are compared for two upper divertor configurations: with the outer strike point on the small angle slot (SAS) divertor target and with the outer strike point on the horizontal divertor target (HT). Scanning the vertical distance between the magnetic null point and the divertor target over a range 0.10–0.16 m is shown to increase the threshold power,

P

th

, and edge plasma power,

P

Loss

, for the low-to-high confinement (L–H) and H–L transitions respectively, by up to a factor of 1.4. The X-point height scans were performed at three L-mode core plasma line average electron densities,

n
¯

e

=

1.2, 2.2 and 3.6

×

10

19

m

−
3

, to investigate the density dependence of divertor magnetic configuration influence on

P

th

. The X-point height,

Z
x-pt

, was further extended across the range 0.16–0.22 m with the more open HT divertor configuration, for which a clear decrease in

P

th

with increasing

Z
x-pt

is observed. The dependence of

P
th

on divertor magnetic geometry is further investigated using a time-dependent probability density function (PDF) model and information geometry to elucidate the roles played by pedestal plasma turbulence and perpendicular velocity flows. The degree of stochasticity of the plasma turbulence is observed to be sensitive to the plasma heating rate. The calculated square of the information rate shows changes in the relative density fluctuations and perpendicular velocity PDFs begin 2–5 ms prior to the L–H transition for three plasmas; providing a crucial measurement of the dynamic timescale of external transport barrier formation. Additionally, both information length and rate provide potential predictors of the L–H transition for these plasmas.
Variational learning algorithms for quantum query complexity
Authors: Wu Zipeng , Hou Shi-Yao , Zhang Chao , Li Lvzhou , Zeng Bei
Published: March 2024

Quantum query complexity is pivotal in the analysis of quantum algorithms, encompassing well-known examples like search and period-finding algorithms. These algorithms typically involve a sequence of unitary operations and oracle calls dependent on an input variable. In this study, we introduce a variational learning approach to explore quantum query complexity. Our method employs an efficient parameterization of the unitary operations and utilizes a loss function derived from the algorithm’s error probability. We apply this technique to various quantum query complexities, notably devising a new algorithm that resolves the 5-bit Hamming modulo problem with four queries, addressing an open question from Cornelissen et al (2021 arXiv:2112.14682). This finding is corroborated by a semidefinite programming (SDP) approach. Our numerical method exhibits superior memory efficiency compared to SDP and can identify quantum query algorithms (QQAs) that require a smaller workspace register dimension, an aspect not optimized by SDP. These advancements present a significant step forward in the practical application and understanding of QQAs.
A noise-robust quantum dynamics learning protocol based on Choi–Jamiolkowski isomorphism: theory and experiment
Authors: Chen Xin-Yu , Gao Pan , Qiu Chu-Dan , Lu Ya-Nan , Yang Fan , Zhao Yuanyuan , Li Hang , Zhang Jiang , Wei Shijie , Xing Tonghao , Pan Xin-Yu , Ruan Dong , Zhang Feihao , Li Keren , Long Guilu
Published: March 2024

With the rapid development of quantum technology, the growing manipulated Hilbert space makes learning the dynamics of the quantum system a significant challenge. Machine learning technique has brought apparent advantages in some learning strategies, therefore, we introduce it to indirect learning in this paper. Based on Choi–Jamiolkowski isomorphism, we propose a protocol that learns the dynamics of an inaccessible quantum system using a quantum device at hand. For an n-qubit system, the learning task can be done iteratively, with operational complexity

O

(
poly
(
n
,
L
)

/

ϵ
2

)

in each iteration, where L is the circuit depth and ε is the measurement error. Then we theoretically prove its noise resilience to global depolarization, state preparation and measurement noise, and unitary noise in gates implementation, where we find the learned dynamics stay invariant. Finally, we investigate the protocol experimentally on a nitrogen-vacancy center system with a natural noise source. The results show that the behavior of a relatively intractable nuclear spin can be learned through an easily accessible electron spin under different noise models, demonstrating the protocol’s feasibility.
Effects of Al and V on deformation behavior and microscopic mechanism of titanium alloy at ultra-low temperature using molecular dynamics
Authors: Zhang Long , Liu Gaoyang , Li Jiayi , He Dong
Published: March 2024

A uniaxial tensile was executed with the molecular dynamics method, while the interaction between Ti, Al and V was described by hybrid potential. The influences of Al and V elements on the plastic deformation behavior and microscopic deformation mechanism of Ti-Al-V alloy were studied under ultra-low temperatures. The results show that the high content of Al and V elements leads to a sudden decrease of plasticity at 300 K. The plasticity is slightly reduced with increasing Al content when the content of V is 3.3~6.2 wt.% at 77 K. However, with the temperature reduced to 50 K, Al promotes the activation of dislocation when the content of V is high (6.2 wt.%) and hinders the activation of dislocation when V content is low (0.4 wt.%). At high V content (6.2 wt.%), the increase in plasticity with increasing Al content is more pronounced. Therefore, the strength and plasticity of Ti6.5Al6.2V increase with decreasing temperature.
A new strategy for insulators to improve the ability of semiconductors to reduce Cr (VI)
Authors: Ye Junchen , Wang Dianhui , Zhong Yan , Liu Hao , Wang Wenyi , Wei Nini
Published: March 2024

Insulators have always been a kind of material that has not been valued in the field of catalysis. In order to expand its application in the field of photocatalytic treatment of heavy metal ions, a series of CdS/SrCO3 catalysts are prepared. XRD proves the successful synthesis of the composite catalyst, and TEM reveals the tight connection between CdS and SrCO3. Transient photocurrent and electrochemical impedance spectroscopy show that the composite catalyst has a better electron-hole pair separation effect and electron transport rate than the two single-phase materials. The catalyst has excellent photocatalytic properties and good stability. Finally, the reaction kinetics in the process of photocatalytic reduction of composite catalyst is discussed.
Front-End Board for large area SiPM detector
Authors: Venettacci C. , Fabbri A. , Petrucci F. , Mari S.M. ,   the JUNO collaboration
Published: March 2024

Silicon PhotoMultipliers (SiPMs) are widely employed for several applications, such as High Energy Physics experiments, as well as other research and industrial fields. SiPMs operating at low temperature, in particular, are the most interesting application for the new large particle detectors for neutrinos and dark matter experiments. In this work we present a low-noise, high-speed front-end electronics (Front-End Boards, FEBs) for large area SiPMs to be employed in the JUNO-TAO experiment for rare event searching. The FEBs are able to manage the signals coming from a 25 cm2 SiPM tile, showing single photoelectron resolution better than 13% and dynamic range up to 250 photoelectrons. A careful approach to the front-end electronics design has shown to be critical in order to fully keep the exceptional performances of the SiPMs in terms of single photon detection, dynamic range, and fast timing properties. The sub-nanosecond timing properties make them suitable to work with the typical mixtures of liquid scintillators currently being used in particle and astroparticle physics experiments. The JUNO-TAO detector will achieve an energy resolution better than 2% at 1 MeV by the use of state-of-the-art SiPMs operating at -50°C. A dedicated readout system has been developed in order to collect and digitize the ∼8,000 channels needed to ensure the requested performances. A complete test report about the performance of the pre-production FEBs batch will be presented, showing the solution taken to ensure a high stability and reproducibility of the results.
Design and implementation of neural network based conditions for the CMS Level-1 Global Trigger upgrade for the HL-LHC
Authors: Bortolato G. , Cepeda M. , Heikkilä J. , Huber B. , Leutgeb E. , Rabady D. , Sakulin H. ,   the CMS collaboration
Published: March 2024

The CMS detector will be upgraded to maintain, or even improve, the physics acceptance under the harsh data taking conditions foreseen during the High-Luminosity LHC operations. In particular, the trigger system (Level-1 and High Level Triggers) will be completely redesigned to utilize detailed information from sub-detectors at the bunch crossing rate: the upgraded Global Trigger will use high-precision trigger objects to provide the Level-1 decision. Besides cut-based algorithms, novel machine-learning-based algorithms will also be included in the Global Trigger to achieve a higher selection efficiency and detect unexpected signals. Implementation of these novel algorithms is presented, focusing on how the neural network models can be optimized to ensure a feasible hardware implementation. The performance and resource usage of the optimized neural network models are discussed in detail.
An H- surface plasma source for the ESS storage ring
Authors: Dudnikov V.
Published: March 2024

For H- charge exchange (stripping) injection to European Spallation Source (ESS) storage ring it is necessary to have H- ion source with a current of ∼90 mA, pulses duration 3 ms, and repetition of 14 Hz (duty factor ∼4%) extendable to repetition up to 28 Hz (df ∼8%). Magnetron surface plasma H- source (SPS) with cesiation and active cathode and anode cooling is one of the possible solutions. Brookhaven National Laboratory (BNL) magnetron SPS can produce H- beam current of ∼100 mA at ∼2 kW discharge power and can operate up to a duty factor of ∼1% (average power ∼14 W) without the active cooling. With active cathode and anode cooling it is possible to increase average discharge power up to 140 W(df 8%).For the delivery of the beam to Radio Frequency Quadrupole (RFQ) it is possible to use a short electrostatic Low Energy Beam Transport (LEBT) as in Spallation Neutron Source (SNS).
Effect of fertilizer discount on fresh fruit bunches production and Nutrients in North Sumatra Indonesia
Authors: Lubis Muhammad Mahadani , Abror Muhammad , Djuhjana Jajan
Published: March 2024

The low price of fresh fruit bunches a couple of years ago forced oil palm companies to make some efficiencies in the whole business process, including discounting the fertilizer expenses, which consequence in the Fresh Fruit Bunches (FFB) production declining in the first and second years onward. Reviewing the effect of fertilizer reduction on FFB production in commercial fields was challenging due to being confounded with many factors, including estate condition, infrastructure, climate, social, and management. Therefore it was better to assess from trials that tested the application of N, P, K, and Mg fertilizers with different rates to oil palm in a different locations on mineral soil in North Sumatra. Those trials illustrated that fertilizer discount would correct the FFB production accordingly from 3 up to 84%. In addition to this, climate, leaf nutrient uptake, and palm age play an important role in the decreasing FFB. An adequate water supply from the rainfall would stimulate a better leaf nutrient uptake and, therefore, palm more tolerant to fertilizer discounts. On the other hand, palm planted on the terraces, which are at a high risk of fertilizer leaching out and poor soil cation of subsoil, would be more sensitive to fertilizer discounts. Fertilizer discount, of course, would reduce the nutrient supply to the palm accordingly and consequently to FFB production for two to three years forward, therefore it was suggested to cut off the less response of specific nutrients only if possible.
Efficacy of herbicides and reductant at different levels to control invasive tall reed (Phragmites karka) in oil palm plantations
Authors: Anggraeni L W , Putri P H
Published: March 2024

Controlling Phragmites karka, a highly invasive weed, is critical for peat areas since this species is a significantand hard-to control weed in oil palm plantations. Herbicides are one of the most effective and efficient tools for controlling P. karka, and their use is increasing due to their ability to provide rapid and long-term results. However, herbicides must be applied responsibly and carefully to minimize any environmental impacts. The study included an evaluation of the effectiveness of several combinations of herbicides on P. karka in an oil palm plantation and a comparison of their efficiency and cost. Results showed that combination of 1.8 L/ha glyphosate, 0.045 L/ha topramezone and 0.3 L/ha reductant Y (G7) has a promising result in controlling P. karka (weed mortality of 97% until 8 WAA and 12% regrowth until 12 WAA) and was more cost-effective compared to estate practice, reducing cost up to 0.43% per hectare because of the use of pesticide reductant. The use of reductant technology in this treatment also showed an effectiveness in reducing application frequency. This study demonstrates that herbicides can effectively and efficiently control P. karka in oil palm plantations, especially in peat land. Reductant can be one of the solutions to reduce the use of herbicides without lessening the efficacy, affordably, and sustainably.
Infestation of parasitic wasps from nettle caterpillar Ploneta diducta Snellen (Lepidoptera: Limacodidae) in oil palm plantation
Authors: Murgianto F , Setyawan Y P , Edyson  , Saputra H M , Prabowo L A , Hidayah A L , Ardiyanto A
Published: March 2024

The nettle caterpillarPloneta diducta(Lepidoptera: Limocodidae) is the leaf-eating caterpillar of oil palm that emerged in Central Kalimantan. The identification of hymenopteran parasitic wasps as natural enemy will help the planters to take action to conserve agronomy practices. The census ofP. diductawas carried out in PT Windu Nabatindo Abadi Central Kalimantan starting in January until August 2022. The population ofP. diductawas found only in three blocks (±100 ha), with a total population is 52 larvae. Of the total population, 92% is unparasitized larvae and 8% is parasitized larvae.P. diductalarvae found are reared in the insectary and observed the emergence of parasitic wasps. There were three species of parasitic wasps that infectedP. diducta, namelyApantelessp. (Hymenoptera: Braconidae),Goryphussp. (Hymenoptera: Ichneumonidae) andXanthopimplasp. (Hymenoptera: Ichneumonidae). Parasitic waspApantelessp. was a gregarious parasitoid and both speciesGoryphussp. andXanthopimplasp. were solitary. From these wasps, the highest infestation byXanthopimplasp. (9.6% parasitism rate) followed byGoryphussp. (3.8% parasitism rate) andApantelessp. (1.9% parasitism rate). Conservation of this insect by intensification of flowering plants can drive the wasp population and its function in oil palm plantations.
Resistance of oil palm seedlings against red spider mite attack through boron fertilizer application
Authors: Murgianto F , Hidayah A L , Edyson  , Ardiyanto A
Published: March 2024

Red spider mites are one of the pests that attack oil palm seedlings, especially in the dry season. The damage caused by red spider mites in oil palm nurseries turns the leaves brown and necrotic and the growth of seedlings becomes weak and prone to infection with various types of disease. The objective of this study was to assess the effect of boron fertilizer application on red mite attacks in oil palm nurseries. There are four boron concentrations tested in this experiment (0, 0.5, 1, and 1.5 ppm). Each treatment had one seedling, laid out as a randomized block design, and each treatment was replicated ten times in the nursery area. In this study, there was no artificial infestation of red spider mites, but red spider mites were allowed to attack naturally. The population of red spider mites declined in the application of boron fertilizer solution with a concentration of 1 ppm, which reduced by an average of 44.9a individuals/leaf (decreasing population to 69%). Meanwhile, in oil palm seedlings with no application of boron fertilizer (0 ppm), the population of red spider mites increased with an average of 40.8b individuals/leaf. An increase in boron content in leaves correlated with a decrease in red spider mite populations that attack oil palm seedlings. In this experiment, the resistance of oil palm seedlings to red spider mites attack is influenced by the boron nutrient content in the leaves.
Physical, biochemical, and Physiological changes on oil palm (Elaeis guineensis L. Jacq) seeds throughout short-term storage
Authors: Arif Mohamad , Ilyas Satriyas , Widajati Eny , Qadir Abdul , Suprianto Edy , Palupi Endah Retno
Published: March 2024

Seed deterioration is an inexorable process, including on oil palm (Elaeis guineensis L. Jacq) seeds which are categorized as intermediate seed type. Seed deterioration rate can be predicted through physical, biochemical, and physiological parameters. This experiment aimed to study physical, biochemical, and physiological changes in oil palm seeds in short-term storage. The experiment was conducted in a 2-factors of nested design. The first factor was storage temperature: open storage (24.2 − 30.5°C; RH 48.6 − 82%) and controlled storage (22.0 − 27.7°C; RH 43.9 − 82.1%). The second factor was storage packaging: single polyethylene (PE) plastic and double PE plastic, which was nested to the first factor. Oil palm seeds of Dura (D) x Pisifera (P) variety DxP PPKS 540 were obtained from the Marihat Business Unit of IOPRI. Results showed that during 6 months of storage, the seed moisture content (SMC) decreased in all treatments, even though the final SMC (11.2-11.4%) was still at a safe level for oil palm seed storage. Significant changes on fatty acid compositions of the oil palm endosperm were not found. Seeds could be stored for 3 months under controlled storage without a significant reduction in the germination percentage compared to those of fresh seeds, while open storage significantly reduced germination 2 months after storage. Germination percentage was not correlated with fatty acid content in the endosperm. The highest germination speed index was detected 2 months after storage in both storage conditions.
QField for QGIS application for oil palm agronomist’s field visit and assessment
Authors: Dzulfansyah D , Suswanto T , Karjono  , Sugandi A
Published: March 2024

In formulating fertilizer recommendations, an agronomist has to visit the estate to assess the actual oil palm growth/condition and other factors such as nutrient deficiencies, field conditions, drainage issues, pest damage, etc. Conventional field assessment using manual handwriting requires a lot of paper and also results in double-handling of work when transferring the data into digital format. Other printed data such as block, soil, and terrain map are not practical to be used in the field or loaded in Androzic or Avenza Maps applications which are not interactive and cannot handle aerial photo data of the estate. An android application, QField for QGIS, has been explored and utilized to replace the conventional field assessment method. To start making an assessment, the agronomist has to tick the smartphone/tablet display to pop up the assessment form. Block data such as block name, leaf/soil analysis result, soil type, rainfall, etc., will be automatically shown, specific to the block where the agronomist is. The agronomist can then fill in the form by selecting multiple choices, such as poor, fair, and good, etc., or typing in the necessary information. The other pre-loaded data, such as block, soil & terrain map, and even aerial photos with original resolution can be shown and overlaid. Capturing georeferenced photographs and tracking can also be performed. Transferring assessment data into a spreadsheet and viewing georeferenced photographs can be done using QGIS software on the computer.
The Evaluation of a Decade Barn Owl (Tyto alba) Introduction in Oil Palm Plantations Central Kalimantan
Authors: Primananda S , Sukarman  , Fitriana C D A , Prasetyo A E , Vui P H V , Siburat S
Published: March 2024

The barn owls (Tyto alba), as a biological control for the rat population, are relatively effective and safe for the oil palm ecosystem. So nowadays, many oil palm plantations are trying to introduce it to reduce the use of rodenticides. This paper’s objective is to evaluate a decade of T. alba introduction in ca 80,000 ha oil palm plantations in Central Kalimantan since the initial releasing three pairs of T. alba in July 2011. We use a quantitative descriptive method to provide the primary data on a monthly monitoring basis, i.e., the T. alba population, including its chick and eggs; the number of barn owl boxes occupied; rat damage percentage and the number of rat baiting applications. The population increment during the year 2011 to 2012 was retarded. However, since the year 2013, the population of barn owl population rapidly increased using a combination of self-released barn owl distribution from field barn owl boxes. It assisted augmentation from barn owl hatchery methods. Based on the monthly census in December 2022, the occupancy rates reached 75% from 4,234 boxes; occupied by 6,390 owls, 1,665 chicks, and 1,531 eggs. The established population of T. alba in an oil palm plantation in Central Kalimantan has reduced the rat damage percentage below the threshold level of 5%. It has no rat-baiting application (zero rat bait).
New tools for measuring stress response
Authors: Putri T K , Kusumawardani A , Nafisah E , Forster B P , Hood-Nowotny R , Caligari P D S
Published: March 2024

Oil palm performance under biotic and abiotic stresses can be measured by various means and growth stages. Verdant is working to develop commercial planting materials that can better tolerate drought and Ganoderma, as well as being efficient in fertilizer uptake. This study aims to identify early screening methods for drought tolerance in oil palm which will allow the selection of seedlings and progenies that can be entered into breeding programs and variety production. The trial was arranged according to a split-plot design with three replications. The main plot is watering (normal watering and drought stress) and the sub-plot was Verdant breeding material that consists of 7 progenies. The 4-month-old seedlings were subject to a water deficit treatment (water withheld for five days) followed by measuring seedling responses: leaf temperature, plant height, and number of leaves, which were combined to give a drought score. Significant differences were found for leaf temperature and drought score. Leaf temperature can indicate stress levels of seedlings as it relates to stomatal opening (respiration and transpiration) and hence photosynthetic activity. These methods are being deployed in a phenomics nursery and the data is used to predict subsequent field performance and yield.
A Population Study of reduviidae insect in oil palm plantation with different historical Darna trima caterpillars’ infestations stages
Authors: Primananda S , Soedijo S , Gazali A , Aidawati N , Sukarman  , Fitriana C D A , Prasetyo A E
Published: March 2024

Enriching biodiversity using beneficial refuge plants can expedite the recolonization process of predatory insects for sustainable control of Darna trima nettle caterpillar infestation in oil palm plantations. The recolonization process of predatory insects, including Reduviidae, will affect the differences in environmental factors, feeding availability, and landscape type. This research objective is to compare the population of Reduviidae insects (predator) in different historical D. trima infestation stages in oil palm blocks with various refuge plants, i.e., Antigonon leptopus, Cassia cobanensis, Turnera subulata, and Nephrolepis biserrata. The research was conducted in an existing oil palm plantation in Central Kalimantan from July to December 2022. An experimental 2-factor nested design involving the history of D. trima attacks and the type of refuge plants was implemented in 8 blocks (ca 40 ha each) to enumerate of predatory insect population using visual observation, sweep net, and yellow trap methods. The study revealed that the dominant Reduviidae species were Cosmolestes picticeps and Sycanus dichotomus. The population of C. picticeps was 35% higher in blocks with no historical D. trima outbreaks are significantly different from blocks with historical outbreaks. In both locations, the highest populations of Reduviidae insects were found in C. cobanensis and N. biserrata plots at 61-72 individuals and 58-67 individuals, respectively. Combining both refuge plants in oil palm blocks exhibited the most significant potential as a microhabitat for Reduviidae insects and for enhancing recolonization. To further enhance the role of S. dichotomus as an environmental service in the agricultural ecosystem, it is necessary to study proper propagation and augmentation techniques in oil palm plantations.
Effect of Beneficial Microbes on Macronutrient Uptake and Oil Palm Seedling Growth in Peat Soil
Authors: Kalbuadi D N , Darmawan  , Pulunggono H B , Santi L P
Published: March 2024

Peat soil has low fertility due to low content of macronutrients, such as N, P, K, Ca, & Mg. Efforts that can be made to increase nutrient availability and nutrient uptake for plants on peatlands are the utilization of beneficial microbes such as endophytic bacteria and arbuscular mycorrhizae. This study aims to identify the role of endophytic bacteria and arbuscular mycorrhizae applied to peat soil media to help increase macronutrient uptake and the growth of oil palm seedlings (main nursery). This study was conducted in June – December 2022. The peat soil sample was collected from oil palm plantations located in Siak Regency, Riau, with coordinates 0°45′22″ N, 101°44′27″ E. The experimental design used in this study was a completely randomized design (CRD) with 8 treatments and 5 replicates. The treatment given in this study was a variation of beneficial microbes with zeolite as the carrier. Beneficial microbes used in this study were arbuscular mycorrhizae, namely Glomus sp, and endophytic bacteria, i.e. Burkholderia cenocepacia and Pseudomonas fluorescens. Parameters observed in this study were plant growth (every 1 month) and leaf nutrient (6 months after planted). The results of this study indicated that the consortium application of endophytic bacteria and arbuscular mycorrhizae was the best treatment which was shown to have the best growth of oil palm seedlings compared to all treatments with plant height increment of 55.5 cm; stem diameter increment of 34.3 mm; and the number of fronds addition as many as 11 fronds. This is also supported by macronutrients content in the leaves of oil palm seedlings such as N, P, and K.
Identification of oil palm tissue culture contaminants by using DNA barcodes: preliminary results
Authors: Wening S , Pratiwi D R , Nazri E , Prasetyo A E , Yanti F
Published: March 2024

The success of oil palm tissue culture is constrained by the microbes contaminating cultures in the laboratory. Accurate identification of contaminant species leads to the right strategies for solving the contamination problem. This research was done to identify contaminant species at the Indonesian Oil Palm Research Institute Tissue Culture Laboratory at its stages by using DNA barcodes. Bacteria identification was done by 16S rRNA sequencing, while fungi identification was done by ITS region sequencing. Preliminary results showed that bacteria and fungi were identified in the laboratory’s stages of the tissue culture process. Four species were identified in the dark room, two in the light room, and four in the advanced light room. The identified bacteria were Bacillus subtilis, Streptococcus parasuis, Priestia megaterium, and Bacillus sp. The identified fungi were Tritirachium candoliense, Penicillium citrinum, Irpex laceratus, Aspergillus reticulatus, and Perenniporia tephropora. More data is needed to determine the right strategies to control the contamination problem.
Enhancing Oil Palm FFB Yields by Water Management: Sumber Tani Agung Resources’ Experiences
Authors: Nadaraj Sundian , Hutabarat Eriston , Thandapani Pupathy Uthrapathy
Published: March 2024

Oil palms (Elaeis guineensis) are generally able to grow economically on various soil types, especially across the regions of Malaysia and Indonesia. However, Fresh Fruit Bunche (FFB) production was lesser in flood-prone areas. In Sumber Tani Agung Resources (STAR), two estates namely (i) Seret Ayon (4289 ha) and (ii) Lembah Bawang (2511 ha) were facing problems of frequent flooding. Annual rainfall of these two estates would fall within 3500 mm - 4000 mm. Out of this, almost 30-40% of the total annual rainfall was recorded in the period of October-December. Furthermore, during the same period, high rainwater from the Forest Reserve of Bengkayang resulted from high water volume in the streams/rivers running across these estates. This caused high incidences of flooding. Therefore, a yield improvement program was embarked on to arise the existing height of riverbanks, literally speaking an ‘embankment or bund management’ on both banks of the river. A survey should be conducted first to demarcate areas that are prone to flooding incidences. Based on the survey results, areas that need improvement by ‘embankment’ would be identified and actions such as construction of flap-gates, building of embankments, and construction of drainage/reservoirs can be made. Outlet drains were desilted and thus, improved the water flow for smooth removal of excess water during the high pour and flooding seasons. FFB yields were satisfactorily increased from 11-14 mt/ha/yr during 2017-2018 to 25-33 mt/ha/yr in 2022. Besides improving FFB yields, palm growth also satisfactorily improved in frequently flooding areas, especially after three years of water management by embankment. In this paper, the commercial FFB yield of Seret Ayon Estate and Lembah Bawang Estate was collected and compared to those from before and after the implementation of efficient water management by embankment.
F1 Hybrids in oil palm
Authors: Forster B P , Caligari P D S , Nur F , Cahyadiati M , Rusfiandi H , Humaira A , Killian A , Nelson S P C
Published: March 2024

F1 Hybrid production in oil palm (Elaeis guineensis) is a reality. F1 Hybrids have the potential to provide massive increases in yield as demonstrated in a range of crops. Verdant has the intellectual property and “know-how” to produce haploids and double them to give doubled haploids. Doubled haploids are fertile and 100% homozygous (genetically pure lines), making them ideal as parents for F1 Hybrids. There has been no genetic modification. Verdant now has a collection of Dura and Pisifera doubled haploids that span the genetic diversity of oil palm from which parents can be selected based on genetic contrasts (using Diversity Array Technology). The first F1 Hybrid crosses (Dura x Pisifera) were made in 2019 and field progeny trial testing started in 2021. Performance in the field is being monitored by a range of physiological tests, but ultimately on palm product yield per hectare plus commercially significant secondary traits, such as disease tolerance, will determine selection. The intention is to start commercial F1 Hybrid seed production in 2029. A phenomics nursery has been set up to correlate seedling physiological traits with yield with the aim of developing early indicators for yield potential and to screen for variation between crosses for 1) Ganoderma tolerance, 2) nutrient uptake, and 3) drought tolerance. Genotyping is also being deployed to identify and select heterotic combinations that result in hybrid vigour.
Efficacy of Chromafenozide Insecticide to Control Tirathaba rufivena and Its Impacts on Oil Palm Pollinator E. kamerunicus
Authors: Happy Nur’afni R , Saepuloh Apit
Published: March 2024

Newly marketed insecticide known with active ingredient Chromafenozide claimed to be potent against various lepidopterous insects, but at the same time almost non-toxic to non-lepidopterous species, including pollinators, predators and parasitoids. This trial aim to evaluate the effectiveness of Chromafenozide insecticides to control population of Tirathaba rufivena in oil palm planted on peat soil and its impact on pollinator weevil, Elaedobius kamerunicus. The trial was divided into two parts which are field assessment of insecticides efficacy and laboratory assay to know the direct effect of insecticide application on E. kamerunicus. Besides Chromafenozide, insecticides used in this trial Cypermethrin and Bacillus thuringiensis var kurstaky as comparison. The results of efficacy test showed that Tirathaba infestation decreased significantly in the Cypermethrin, B. thuringiensis, and Chromafenozide treatments compared to control. However, among these treatments did not show a significant difference. Nevertheless, each of the tested insecticide caused significantly mortality to E. kamerunicus. E. kamerunicus mortality rate of each insecticide treatment showed that Chromafenozide was less detrimental as compared Cypermethrin, but significantly detrimental to B. thuringiensis. B. thuringiensis was not significantly different compared to control.